Intro's the best. Graphics are good, but levels could improve "readability" (more contrast, different colorus or parallax).
The game has a lot of charm, but it's frustrating. Controls don't feel right and the gameplay is unforgiving. I dreaded the sections where I had to use the grappling hook, cause I didn't have much control over it. A grappling hook should be fun!
But what really made me quit was the amount of waiting for all those lights to align so I could go through the levels.
Regarding audio, it's ok. Background ambience feels ominous, while the character death sounds are cute.
A small "bug" I encountered was that the timer started before the level, though it's really something minor.
In brief, game looks really cute, but could use some polish.