pretty good.
The best thing about this game was the ability to set your own difficulty. More games should have that. The game was well developed.
Here are the cheats for those that want them. Think I'm missing one though.
painless-no rings taken when hit
blind- 100%% darkness
propeller- Fly indefinitely
lunar- Super jump
super- fast speed
puppet- play as tails doll
rampage-complete invincibility
spawner-infinite lives
dream-play tails ending
level cheats
level 1 maze
level 2 springs
level 3 spike
level 4 pitfall
level 5 boulder
level 6 fork
level 7 loop
level 8 drain
level 9 trap
level 10 doom