Sanctum 2 Shoot the Ones That Get Through

Every map starts in the building phase. You place walls to twist the aliens' path into a long, painful crawl, and towers where that crawl hurts most. Then the wave hits, and instead of watching from above, you jump in with a gun. You run the maze you just built, plug the gaps your towers miss, and shoot the big ones in their weak spots. When the wave breaks, you get a breather to rebuild and upgrade before the next one comes. Enemies pop satisfyingly when they die, and the soundtrack carries the whole thing along.

You pick from four character classes, each with its own weapons, strengths and weaknesses. From there, a loadout of towers, weapons and perks is yours to choose, and the differences are real: one class rewards a damage boost on the last shot of the magazine, another plays better perched up as a sniper. Rank up and new weapons, towers and perks keep coming. Feeling confident? Add Feats of Strength to make the game genuinely hard, and expect to rethink your whole setup until a map finally falls.

Up to four players can run the campaign together, and this is where the game is at its best. You plan the defense as a team, split the money, cover different lanes, and then improvise when a wave comes in from three entrances at once. Some maps seem built for exactly this kind of teamwork, each player holding a role. One more wave turns into one more map turns into a much later bedtime. The campaign is playable solo too, whenever you want.