Sanctum got some well-deserved attention when it was released back in 2011. The unique mixture of tower defense and first person shooting elements allowed for both thoughtful gameplay and wild stretches of blasting aliens with guns. With Sanctum 2, Coffee Stain Studios decided to make some tweaks to formula, upping the action and toning down the towers. The result is a game that feels very different from the original, despite being built around the same core concept.
The basic idea behind Sanctum 2 is to defend your base from waves of invading aliens. Some aliens are tall, some of them fly, and others look like ambulatory pimples from a Dali painting. No matter what they look like, they're headed towards your core, and that's a bad thing. Your job is to place a bunch of turrets and towers in their way to try to stop them. And when that fails, you've got a decent arsenal of guns you can whip out to get the job done.
Each level begins with the character select screen where you choose one of four people to take into battle. Characters have different abilities that suggest a particular playing style. Haigen carries a shotgun, has more health than the other characters, and deals extra damage when close to enemies. SiMo uses a sniper rifle and is especially good at bringing pain to aliens by hitting them in their glowing red weak spots. Skye is the most balanced character and has a nice double jump ability, while her sister Sweet carries the massive flame weapon Rex. The character classes lend some variety to co-op games, but if you happen to be going solo, any one of them will do you just fine. New towers and weapons can be earned and equipped as you progress through the stages.
Levels are divided into waves which quite neatly separate the tower building and action sections of the game. When all is quiet on the battlefront, it's time to upgrade and build. Sanctum 2 provides two basic resource types: tower cores and currency. Cores determine how many base towers you can build, i.e. place one block, use one core. Currency is used to build and upgrade offensive towers. Once you've laid a foundation for the monster maze, start adding some blasty things at key choke points to maximize their damage. But hey, you know how to play a tower defense game, right?
Once the enemies are active, it's first person shooter time. Control your chosen character as you frantically hit enemies with everything you've got, swapping weapons to minimize reload delays and aiming for weak spots as best you can. It can get frantic when aliens pile up and attack the core, but if you survive you'll be rewarded with resources. Just what you always wanted!