This is a very well made entry, one of the best I've played so far and the critique is not to detract from it.
It does feel like the difficulty curve is a bit over the place, some levels are very, VERY difficult, and the next level is then very easy. Some of the additional gameplay mechanics (zap namely) feels inconsistent and I never got the feel for it.
Occasionally I felt like the jumping height was a bit inconsistent.
All that aside I had lots of fun and am very impressed with it. Good job :D