Cool game! Devil Daggers feelings :D
But I got stuck in geometry too many times (ramps included), and I didn't get how the bomb works. In level 2 I can't shoot the laser guy at the top, and I got enemy respaw 3 times because of it...
Some suggestions:
ALT+ENTER to full-screen mode.
mouse sensitivity is a must.
improve level geometry to not get stuck so often.
simple tutorial explaining basic mechanics and controls (can be a simple intro text)
Kudos for the frenetic gameplay and the great sound design. ;)