It's a good base for a mech game. Love the character sprites, they are adorable. Needs some balancing and tweaks though - like screen shakes, reverb on the steps. Minigun feels weak due to it's weak audio, and rail gun is OP. Also the bomb launcher acts weird - like it doesn't add a proper impulse vector to the bomb? I dunno.
Anyway - keep it up, looking forward to more progress on this!