Thanks for the great feedback and suggestions everyone -- it inspires us to push even more towards making the best game we can.
Yes, we're very excited to have Osmos on Steam as well! It's just the demo for now, but come this summer...
To respond to some of your comments:
- the full verison will definitely feature more gravity levels: bigger/faster/more-complex systems, moving attractors, etc.
- music: nothing nailed down yet, but yes, more wonderful ambient electronica coming your way. (some with "procedural" variation.)
- visuals: been hard at work on this, trying to make things richer/more-alive/organic while keeping that soothing, minimalist feel. (not obvious.) feel free to check out some of our experiments at:
http://vimeo.com/user989434/videos. agreed on the walls as well: they need work.
- pre-order: yes, i'd like to do this.
- player/level stats: we're planning to add some. (and possibly a "unique" scoring mechanism.)
- more mote-types/abilities. there are a number of great suggestions in this thread. all i can say is... we're working hard on it, and keeping a few surprises up our sleeves.

Oh, and don't forget to vote for your favorite finalist in this year's IGF. Voting closes this Friday:
http://www.igf.com/audience.phpCheers,
Eddy