The Combat should be easier, and there should be more upgrades.

Needs work, as is understandable in a demo.

GOOD:
Graphics are nice. I especially like the robots designs.
Music is good, especially for the boss.
Movement is fluid (not including attacks) although can be messy with angled platforms.

BAD:
The attack in mid-air actually stops you movement so sometimes I forget about this and fall into a pit.
The weapon/shield upgrades don't make sense. They seem to get worse with every pickup.
Combat is tedious and too hard on the defensive.
As a 2 player game, it's got that bad thing Skylanders has. You have to fight for screen access and gears.
A lives system shouldn't be here - especially a shared one. Once I did lose all my lives, my character disappeared but the game kept going.
It's hard to tell a background crate/wall from a platform one.

EXTRA:
I suggest zooming in, especially on the boss. Apart from not evoking a good battle experience, I'm missing all the detail on the player/enemy sprites.