Controls are nicely tuned to envornment, but the friction could be a bit bigger, I felt like I was walking on ice. Levels are desigened nicely teaching you as you progress. Background is a bit flashy and demanding too much attention. Smiply changing it's color to be a bit more darker or transparent would highlight foreground, which is important for gameplay.
Great job. Platformers are very hard to implement in such short time. Cheers!