Charming, but not the best.
I was only able to play a level or two, but I noticed some things that could use some improvement:
1) The enemies in the early levels take way too many hits to kill. Either change that or this:
2) The health ors only healed one hit point. I mean, even if your character is only up against one foe at a time, he damage just builds up too much for healing.
3) Moving left and right when you need to move left and right suddenly isn't working too great. The bad guy keep slipping from one side to the other and I can't turn quickly enough to get to him.
4) The game runs a little slowly. At least, the graphics do.
Anyway, if you make a "Protec the planet 2," try and make sure that it's not just easy and aesthetically pleasing, but really engrossing.
All in all, not too bad.