Johnny Ringo said:

Okay here are two games I haven't played or even thought about in years. Two games that were frustrating yet rewarding, two games with sequels [of sorts] that I never got around to checking out...

ANOTHER WORLD [aka OUT OF THIS WORLD]
http://en.wikipedia.org/wiki/Another_World_%28video_game%29
http://www.youtube.com/watch?v=dNeayv-OTK0&feature=related
http://www.youtube.com/watch?v=LIR-APjbU4o&feature=related

FLASHBACK
http://en.wikipedia.org/wiki/Flashback_%28video_game%29
http://www.youtube.com/watch?v=gJyP5efESaI&feature=related
http://www.youtube.com/watch?v=7AQvgbdtIJk&feature=related

I played both those two games and their sequels. You could only get Heart of the Alien, as far as I knew/know on Sega CD, which neither I nor anyone I knew had. I replayed OOTW/AW on a SNES emulator not too long ago and started looking into HotA again. I found an emulator and played through it. I think if you could handle a replay of OOTW, you would really did HotA since it's mostly more of the same thing, but maybe a slight advancement.

I also replayed Flashback around the same time. That game is so well balanced, I found it extremely compelling. 18 years later and I think it's held up remarkably well. My friends and I thought about making a game in XNA a couple years back and that was one of the ones that I thought was 1. simple enough that we could mimick it and 2. awesome enough that people would want to play it. The sequel, Fade to Black, was pretty good, if I recall. I remember getting it for my PC on release day and being pretty thrilled. It probably hasn't stood the test of time quite as well, however.

There was a new game called One Escapee (http://en.wikipedia.org/wiki/OnEscapee (New in 1997, I guess...)) that was supposed to be a spiritual successor to both OOTW and Flashback. I was pretty stoked, but I couldn't get more than about 5 minutes or so into it. Either the game was buggy, or the player was. ;)