Simplicity is a winner!
The other reviewers have pretty much already said what needs to be done to improve the game. I don't want to be a broken record, but as they mentioned you should gain health when dissolving/sucking up the paint. In addition to that stale suggestion, boss battles against maybe a huge block of paint or something of that of nature would be pretty cool too. I loved the simple controls and fast-paced gameplay, and the frugal graphics were nothing to sneeze at either. Based on your first flash game, I can't wait to see what else you're cranking out! Keep up the good work!