Run-On v2.4 by WiL/KKairos (2001)
Procedurally generated runner/shooter. When getting in I intended to play it just ten minutes out of curiousity, but I found it genuinely fun so I kept on going. The problem is, it's a long game. After several sections (each one having nice changes, the best being the road) the game quits being an endless runner, and shifts into gradually worse, more bugged and less fun sections. I finally quit when the game started looping the level counter. It's good, but should've ended much, much sooner than it has.