Simple, but engaging gameplay, the movement felt smooth and I liked the sprite work and nice contrast between background and foreground - very readable. Also having controls displayed at all times really helps.
Now for the more critical part :D I don't see the purpose of sprint button. It makes character move faster, which I want at all times, since the game is timed, so it would seem that I want it pressed constantly. So it's rather pointless, the character could just move at increased speed and nothing would change. The music was nice and atmospheric, but when time was running out, the switch felt a little jarring (though I know it's hard to make a smooth transition, especially in such short amount of time).
Overall, great job, this isn't anything major :)