TBH, I don't like Captain Forever. It seems to suffer from what amounts to poor design to me, but meh. It attempts to do something different, and I can't really give it flak for that.
I also played ROM CHECK FAIL. While fun, sometimes it's downright unfair. And choosing to limit the movement of the Space Invaders ship to just left and right was, again, poor design choice. Especially on the levels with those damn ghosts....*shudder*