Angstron 2

This game follows the story of Angstron, but is rather a tactical first person shooter. You don't get those fancy protections and 100 HP from other games. You're hit, you're dead.

But this game doesn't aim to be impossible to beat. You don't have to aim precisely because the plasma pellet you shoot has a electrical property of disabling (or even destroying) the positronic connections from the robot's CPUs. That way you can destroy them not having to aim bullseye.