Attack of the Paper Zombies is an indie RTS game that feels more like space marines versus bugs than the zombie apocalypse. You control a handful of heavily armed marines on a graph-paper arena with scattered zombie spawn-points, and must mow down ranks of advancing attackers, ultimately killing the cthulhoid creatures that spawn them, taking over all spawn points.
The game lacks the typical resource extraction component of conventional RTS games, but instead has a tower defense-like element in which you can build turrets at fixed locations, as well as calling down a chemical strike on a zombie-infested area, laying minefields, and creating a heavy weapons targetting area. Additionally, the weapons of your marines (initially all have rifles) can be upgraded to flamethrowers or sniper rifles (useful for taking out spawners at range). All of these consume "BPs," however, and the only way to earn more is to capture spawn points.
Although the game is continuously moving, and has a player-skill component, it feels much more cerebral than a typical action game, with careful planning and use of your constructions and special weapons critical to winning with your limited BP budget.
The tutorial is nice and fairly short; there are only a handful of designed levels, but there are also randomly generated ones (at a player-selectable difficulty level).
Graphics and sounds are obviously not startling, but the gameplay is solid and entertaining.