Wait, did you hear anything when you were pressing the button?
I'm getting the same problem and I hear a noise
If you hear a noise, that Just Means you dont have enough Money for the fuel mix you selected! Hope this helps :P
Ah! Ok thanks.
You're welcome! This Will be explained in the tutorial of the upcoming mobile version, since lots of people seemed to be confused by this.
wait wut?
Yeah, there's a mobile version of Space Boomers. It's been out for a while now!
