it's funny how this flappy bird game has seemingly randomly taken off. I had a "default gravity, user input = up" game on my 2001-era palm pilot, but it worked by smoothly changing acceleration instead of the jerky ups of flappy dick. I played it in class, and it inspired me to do my big impossible graphics cs course final project on such a game, only it was a 3d tunnel game textured with shit I pulled from quake3. and your ship had a sweet shield to start that would like gently bounce you off the edge.

oh I found a super fancy version of sfcave on youtube. mine was black & white