I rearly download the games here; but judging by the screenshot it seemed like it had potential. (You should display it) I'm glad I used up my limited time to visit this thread.
After playing it I'd say that it is the best game small game I've tried in about 6 months. With certain larger games on this site, I couldn't play for more than 2 minutes without my stomach telling me to stop torturing myself with boredom; but I ended up playing yours for 10 minutes. 10 minutes is not bad considering my level of impatience and extremely difficult to please nature.
Gameplay seems 8/10 considering there isn't much to do and it isn't very challenging; at least what is there is relaxing. I'll keep it installed on my harddrive, worthy of its disk space use on my computer and I'll even make a start menu shortcut for this one. A definate replay.
The terrain looks decent 7/10, the snake works nicely; you see the sphere pop out a bit on steep hills, but the rest of the snake looks 6/10, it does not look easy to produce. Could do with some clouds or sun in the sky.
As a 'low end user', my frame rate seemed to be below the 20s. So something in there is lagging the gameplay for me. 5/10 performance. I will assume that this much slower than yours; and that you are not using timer based movement.
I'm running on an AMD Athlon FX 64, WinXP, 2048 mb Ram. nVidea GeForce 8400 GS 512mb 567Mhz core clock system.
I hope you continue with this game, and add in level music, different levels of difficulty, enemies and a some extra exploration capabilities, secret pathways and power-ups. If you are not continuing with this project then it is a shame, because it has limitless potential once you add in extras and if you feel like it, multiplayer.
Nice work.