It seems you took my last comment the wrong way, but here's a more in-depth review and criticism:
At first, I found the orientation of the game slightly confusing. The graphics led me to believe there would be gravity, but then when there wasn't I was a bit unsure what was going on. It took me a few playthroughs to get it.
I found the idea of 'blowing enemies up' quite amusing, while not causing any negative effect to the rest of the game. Well done on that.
The additional method of crushing enemies with rocks was quite a nice feature, and perhaps more rocks on the level would allow it to be better used.
Maybe it's just my mouse, but sometimes while I was blowing up the enemies it would release them.
The slowness of breaking the blocks was quite annoying, but it looks like you realised that.
My speakers are dead atm so I couldn't judge the sound.
Apart from the fact that the game was underground, I'm not sure how much this relates to beneath the surface. It felt like the same game could be put in any environment and still feel the same. (I know I didn't do this well either)
This feels a lot like a game which I know I played when I was younger, but I can't remember, so you get a bit of a bonus for nostalgia. ;)
If there was one thing I think would make the game better, it would be more variety in enemies. I noticed that new enemies were being added after a few levels, but it felt too slow for the pace of the game.