Interview | 5/22/2014 at 12:30 PM

Indie-Ana Co-Op and the Nerdook Interview

One man development team Nerdook is out to make games

This month in Indie-Ana Co-Op, we're talking with Malaysian developer Sim Yih Chun, the one man development team behind Nerdook Productions and the recently released Vertical Drop Heroes HD. One thread that comes up again and again throughout our talks with devs is the passion they have for making games, and Sim certainly has that. Whether it's Flash-based, board, or full-on PC games, he wants to make games and wants them to be fun.

Co-Optimus: Tell us about Nerdook Productions and how you got started in games development. You’re based in Malaysia, correct?

Sim Yih Chun: Hello, my name is Sim Yih Chun, though I’m more commonly known as Nerdook. Nerdook Productions is actually just one guy (me), and I’m the coder, designer, artist and animator for all the games I’ve released. My music skills are not quite up to par, however, so I usually work with a bunch of musicians on the music for the games, including my wife, who’s just absolutely talented!

Yes, I am based in Malaysia… in the state of Sarawak, on the beautiful island of Borneo. I started my career in the oil and gas industry, and in my spare time, mostly on weekends, I dabbled in Flash game development. I’ve always been interested in games of all kinds… I spent most of the afternoons in my teenage years drawing little cartoon men on cardboard, cutting them out, making custom dice, and, uh, “convincing” my brother to try out the home-made board games I made. When I found out you can make your own games on a computer, I was thrilled: my very first PC game was made using simple VB script in an Excel spreadsheet. In 2010, after a series of rather simple Flash games, I made the surprise hit Cluesweeper, and that led to sponsored games and eventually on to full time game development.

I’ve released 25 games on various Flash portals so far, mainly sponsored by Kongregate, with a combined count of over 50 million plays worldwide for all those games.

Co-Optimus: Tell us about your first full PC title, Vertical Drop Heroes HD.

Sim: Vertical Drop Heroes HD is a complete remake of one of my earliest games. The original Vertical Drop Heroes is about 4 years old now, and that was an early experiment in procedural level design for me. Vertical Drop Heroes HD takes the spirit of the game (“vertical scrolling, procedurally generated, platformer-RPG hybrid”), and overhauls almost everything else. It has a completely new engine, being built in Gamemaker Studio instead of Flash. It has a new game structure, a new level generation system, a lighting system, new artwork, a TON of new skills, enemies, bosses and levels. In the original, you started out as a weak peasant, and opening cages allows you to morph into various heroes. In the HD version, the game generates three random heroes, generated from all the weapons, upgrades and skills you’ve unlocked in previous playthroughs, and off you go on a randomly generated adventure!

The original Vertical Drop Heroes saw you changing your hero class by rescuing other heroes in locked cages

Co-Optimus: Why the transition from Flash to full PC?

Sim: It’s more of a sideways expansion, actually, because I released a Flash game just last month as well. Flash is great to work with, it has a huge audience, and a relatively low barrier of entry, but it has its limitations as well. The main limitation, for me, is the lack of easily accessible graphics acceleration. I experimented with technology like Starling, which allows Flash to access the graphics card of your PC, but found that it was all rather overwhelming. In the end, I switched to Gamemaker Studio and loved how easy it was to get everything going!

Another reason for making full PC games as well is for financial reasons. I have a daughter now, and while the Flash gaming community is awesome, making ONLY completely free to play browser games might not be the smartest financial move, going forward. Therefore, I decided it’s time to widen my horizons, learn new skills, tackle new challenges, and try my hand at making something much meatier than my usual Flash games.

Co-Optimus: What was the inspiration for this game? There are a few different games, such as Rogue Legacy, Castle Crashers, and Ice Climbers, that I’m reminded of from seeing the trailer and playing through it some, but were there any particular games that influenced its development?

Sim: Actually, the main inspiration for this game is the original Vertical Drop Heroes (obviously… haha), and the main inspiration for THAT was an older Flash game called “We Want YOU”, which I think came out way back in 2009. If you search around a bit for screenshots of that game, you’ll notice a similarity right away! I’ve always dabbled in different genres whenever possible, and I felt the best thing about platformers is the sense of immediacy to the action. I combined this with my eternal fascination with random generation, which has been a key part of every single one of my games since the early days, and added a fantasy theme on top: result: Vertical Drop Heroes!

Another key influence for me is Spelunky, which is a wonderful example of brilliant procedural design. I’ve always loved procedural generation, and Spelunky just did it so well… the various enemies and traps led to a whole bunch of hilarious character deaths.

It’s funny you should mention Rogue Legacy and Castle Crashers, because those developers came up from Flash games as well! I am a big, big fan of Rogue Legacy, and Vertical Drop Heroes does have some similarities in terms of the randomised levels and the selection of heroes at the start of the game: but Vertical Drop Heroes takes a slightly different approach to random generation: rather than randomizing the room layouts, I decided to go for a totally destructible, emergent platforming system, with completely randomised levels.

Co-Optimus: How about the overall look and feel of the game? There’s a very distinct aesthetic to the characters, enemies, and levels.

Sim: I’ve always been a big fan of the distinct art style of Dan Paladin from the Behemoth, as well as (more recently) those amazing people at Mika Mobile, developers of Zombieville and Battleheart. They’re all incredibly talented! I draw all the art in my games myself, mostly for cost reasons, and seeing their work, I decided early on that developing a distinct vector art style of my own was something that I had to slowly learn over the years.

The main reason there’s this unique aesthetic to the game is because every single one of the characters, weapons, enemies, bosses and level components were all hand drawn by me. In fact, if you go back in time and play my games from the very first one, you can actually see the art style evolve over the years, before eventually settling into that signature Nerdook style of cartoony people with overly large heads.

Co-Optimus: What’s been the greatest challenge in developing this game? Are there any new features or abilities added for the PC version?

Sim: The biggest challenge in developing this game is having to learn a brand new langauge and program (Gamemaker Studio) after years of getting used to coding in Flash. Everything’s just different, and it took some time for me to get used to everything.

I’ve added lots of features to the PC version, but the biggest one (I think) is the inclusion of multiplayer. The original Vertical Drop Heroes had co-op play, but it was more of a single-screen exercise in pure chaos. Since players have to exist on the same screen, anyone lagging behind will be teleported ahead, with all the hilarious confusion that causes. As you can imagine, I’ve totally revamped that in the full PC version. Local co-op is now split-screen, and leads to plenty of crazy combos and funny events like blowing a hole under your “friend” and dropping him/her straight onto a pit of spikes. On top of that, I’ve also added local network multiplayer, which is something totally new for me. You can play it over the internet as well, actually, but that requires some tinkering around with VPN settings, and so on.

The original Vertical Drop Heroes didn’t really have many unique abilities, and I’ve added a whole lot of new skills for the HD version. Every character gets two abilities, a primary one with more charges, and a more powerful secondary ability with less charges, and this is randomised for each hero, with more being unlocked as you play. I’ve worked hard to make sure each ability has many different uses in different situations: players will eventually figure out that the Fireball not only sets things on fire, but breaks blocks (and chests!) as well: the Ice Bolt freezes blocks and makes them breakable by other missiles: Lightning Bolts electrify any water they pass through, slowly killing anyone trapped inside: you can deliberately fall onto a pit of spikes and swap places at the very last minute with a random enemy with the Swap ability... and so on!

Co-Optimus: What have you learned since you first made “Vertical Drop Heroes” and has that helped with the transition to PC?

Sim: In the original Vertical Drop Heroes, the level generation engine was literally a random generator. It was completely possible to get stuck due to not having the right skills to escape the current generated level, which is.. not very good. For Vertical Drop Heroes HD, I’ve redesigned the level generator completely from scratch, and it now generates pre-designed “chunks” of the level, while varying the details of each part, while ensuring the players will always have a way forward.

I’ve made many, many games with randomly generated parts over the years since the original VDH, and I’ve found that a careful mix of pure randomness and predesigned parts are often the best way to go. I’ve also learned that many of a game’s most memorable parts actually come from the emergent situations caused by a complex interplay between the game’s systems, and hopefully the randomised mix of enemies and skills will lead to many fun moments for the players!

Also, for this transition to a full PC version, I’m working with Digerati Distribution to handle the PR, marketing and distribution side of things: there’s only so much one person can do, after all. They’ve done an awesome job so far of taking that part of the business off my shoulders, and we look forward to many more projects together in the future.

Co-Optimus: Why incorporate roguelike elements instead of a straightforward RPG loot or level mechanic?

Sim: I’ve always been fascinated by random generation, long before the current wave of roguelike elements in games (which makes me VERY happy!). I think every single one of my games so far have had random generation. Here’s a partial list:

Cluesweeper: Solve a randomised murder mystery, minesweeper style! Vertical Drop Heroes: Randomly generated Platformer RPG! Zombies took my Daughter: Fight through a zombie infested, randomised city! Monster Slayers: Assemble a perfect squad to fight through randomised battles! I Am An Insane Rogue AI: Take over randomised buildings as a crazed AI!

And the list goes on! Therefore, a platformer RPG from Nerdook Productions is highly unlikely to be a linear game, and while there are level and XP aspects in the game, I’ve decided to focus on the procedural generation to generate a fresh experience each time!

Co-Optimus: What lead to the decision to make a co-op game?

Sim: As I’ve said, I’m a big fan of having emergent situations occur in a game, and nothing creates emergent situations better than having another fellow human by your side. The sheer unpredictability of a human brain just leads to many possible situations in the game, most of which I have never imagined, but will undoubtedly happen when players get their hands on the game.

Having twice as many skills and twice as many brains in a game leads to many, many times more fun, and making the most fun experience possible for players is the ultimate goal of any game designer!

Co-Optimus: What’s been your experience so far with the Steam Greenlight program? Has it proven to be a good way to get the word out about your game?

Sim: I went into Steam Greenlight fully aware of the various stories about it: long months spent languishing in “the system” for some games, while some other games going viral and breezing past Greenlight easily. Vertical Drop Heroes has been there for close to 5 months now, and is still slowly accumulating the votes required to be Greenlit, so I guess it’s a process where a majority of developers will just have to be patient. There are a LOT of games there, after all, and it’s getting more difficult to get your game noticed out there!

I think it’s been sort of useful for collecting feedback about my game from a wider audience, but mostly I end up seeing it as a long process to go through before I can sell my game on Steam.

Co-Optimus: Do you already have plans in place for what’s next?

Sim: I don’t have any solid plans yet. A lot of it depends on how well Vertical Drop Heroes HD does, and if it’s a commercial success, I’ll definitely be updating many more of my games and bringing them to the desktop. As a man once said, in my all-time favourite book series: “Plans can break down. You cannot plan the future.. The wise man steers!" –Paraphrased from Discworld ;)

Co-Optimus: What are some of your favorite co-op games?

Sim: On the PC, I used to spend many hours playing Real Time Strategy games with my brother against teams of computer AI in Starcraft and later, Warcraft III, though I am not quite sure if that counts! I’ve also spent many hours on Diablo 2 and the original Left4Dead with my friends back in my university days.

I’ve recently gotten into board games as well, which have enjoyed a healthy resurgence into the mainstream recently, and we’ve been having great fun playing games like Ghost Stories and Gears of War: the Boardgame! I’ve even taken some time off to design home-made variants for Descent 2nd Edition… which is probably proof that men will always enjoy doing what they spent all their free time doing in their youth!


We'd like to thank Sim for taking the time to chat with us and answer our questions. Vertical Drop Heroes HD is available now for just $4.49 from, and the Steam Greenlight page for Vertical Drop Heroes HD can be found here.