Robotz DX is a frustratingly difficult shooter with one-hit death that restarts the level, a remake (with some changes) of an obscure Atari ST game called Robotz. The basic set-up is that there is at least one, sometimes more, 'shield generators' on the level that you must destroy before you can kill the robots, after which you must clear the level of robots -- all within 60 seconds.
Levels are pseudorandomly generated, so each time you die and restart, the arrangement of items and enemies may be different, though some obstacles retain position. This does mean that you occasionally get a level layout that is well-nigh impossible to beat, but after you die, it will respawn with an arrangement that is easier.
It has a nice retro feel, and will be liked most by those who grew up on this kind of game and have the skillz to deal with it. It's a shame, though, that there isn't a full-screen mode.
Update: Hit "F' at the attract screen for full-screen mode, and the reviewer reads no stinking manuals. Ahem.