Level 10 teaches us that Sir Isaac Newton was wrong, and heavy object do indeed fall faster than lighter ones. I wouldn't have a problem if it didn't claim to be a "physics" platformer.
For people who have card abilities that don't seem to be working: Look at the name of the ability on the card (not in the popup). Some activation abilities only effect certain types of cards (imperial, xeno, etc). So Strike All Imperial 1 will do 1 strike damage to all Imperial enemies.
Contrary to popular opinion, I think its nice to have a game like this without an elaborate upgrade system. The upgrades that are provided give you a small advantage in certain tight situations, rather than making it so your ship can annihilate everything as soon as it comes on screen. Winning requires skill, not grinding.
To beat the boss, hit him 4 times with flaming stick, then hit him again with flaming stick while he is crouching next to an oil barrel. You have to this 3 times. The first time he attacks by running at you - hit him right after he stops. The second time he jumps causing shock waves - attack him after his third jump. Finally he shoots missiles - run in circles around him until the missiles are gone, then attack him.
Apparently to kill the boss, you have to hit him 3 or 4 separate times with a flaming stick (he should get shocked). Then follow him to an oil pump and hit him as he refills. Repeat until he is dead, I guess. I can't get past him jumping around after the first pump explodes. I get hit by him every time I get close enough to hit him, plus I frequently get stuck on objects.