Cute, but... GAH!
Despite what some people think, difficulty is hard to make as well as hard to complete. I'm impressed with this game overall, but there are some specific areas for improvement.
First, the color-changing character sprite could really have been handled slightly better. Blinking in that particular way is usually best handled as a short-term temporary effect to indicate a status change, such as invulnerability or damage. The persistent color-changing did not create a particularly interesting character, and was slightly hard on the eyes.
Second, there were a few levels where a large amount of movement and clicking were required simultaneously. This is not bad design in and of itself; some of my favourite games involved such ambidexterity. Unfortunately, it felt more like the mousing broke up the keyboard movement action rather than fit with other movements I was making. This could have been because I was using a touch pad instead of a mouse, but some small keyboard-activated green block breaker may have been a better design idea in some places, like a laser or squirt gun.
A couple of controls were sorely missed, specifically a pause and skip option. Pause buttons are nice if you have to drop the computer for a moment to stop the puppy from peeing on the rug, and being able to skip levels that are giving you difficulty is typically appreciated, although I tend not to use skips, personally.
Overall, however, the game was interesting and fun, if short and steeply difficult towards the end. There were a couple of minor complaints which could be remedied with little effort, such as the pause button and making the main character stop blinking. I look forward to seeing future contributions!