Addictive is an understatement
This is a fantastic start for what can become an amazing game.
First, the graphics of this game are smooth and detailed, but not enough to lag up an older computer like mine. The game play is simple to understand.
What I would suggest is to bring in a heads up display showing us our progress (besides what we can check on the achievements page.
The sound is great too fitting for this and very reaxling.
I think what you could do is make this into a storyline of sorts. Make levels give me a reason why I am collecting spirit power or whatever it is and why the red ones need to be redeemed.
Also, when you rank up, make our character look a little different, a little more powerful or faster.
Upgrades would be great, for speed, redeem time, and reduce the amount of power ups we lose if we get hit, or make power ups more effective?
Add these things and you have the lineup for a very, very addictive and amazing game.
As is, I love it already, more so than most games I've played to date. Just these suggestions I think can make it legendary. :)