Really enjoyable demo. I was surprised by how well the jumping physics are suited for dealing with the barrage of projectiles enemies shoot at you. There's some lack of polish and visuals might be somewhat underwhelming, but they create a cohesive whole and shooting stuff just feels good - explosions are on point and enemy fire is easy to see.
As others said, an autofire button would make a great addition - the frequency of mashing gets pretty hard on you after a while. I felt the charged fire of blue/red weapons isn't very useful - it has quite limited range and most of the time it seems to be just faster to kill things with ordinary fire. I think I saw it had some bullet-blocking properties, but it appears to be very situational, maybe I just didn't get used to it well enough. I'd also probably find myself using boost more often if it was possible to initiate it without right/left input.
It's nice that there is an option for basic key rebinds, but I wish gamepad support was a little more robust - it seems like only pad 1 can be used.
I'm looking forward to more news about this game.