Very creative!
But with a few flaws in execution. The art style of this one, like all nitrome games, has a very cute and fun aesthetic, animations are great, and overall a very fun look.
However, when you're trying to kill little bots on the opposite side of the planets, the delay of the drilling is so long that you often end up landing right on top of them and dying, even if you're just the slightest bit off. To say the least, that was a bit frustrating. I still can't beat level 16 because of this :P
However as some other people have been saying, it gets a little repetitive after a while.
Overall a fun time-killer though. Great work!