Looks great, but is pretty much unplayable on a keyboard layout that is not qwerty - I am on qwertz, so y and z are swapped. Please, either bind Z to Y also, or add key rebinding.
- started it a second time, and noticed that you do have controller support! I would add that to description!
Some thoughts: I would put the main HUD at the top - as a player in a vertical scrolling shmup, you tend to look where the enemies are coming from, which is usually the top. Having to constantly glance down, disturbs the flow atm.
The energy especially ran out more often than I would think it would, and it was hard to gauge how much energy I had left, specifically when flying. A hud element showing the energy directly at the players location could solve that. Edit: now I noticed there IS a bar for the energy at the players position. It is way too small though, so hard to notice.
I had a few instances, where I was hit by things without knowing what actually hit me. I identified two instances of this: the first being the hatch that spawns walkers, while I was above the hatch. The second being projectiles of enemies when I was very close. Both of these instances are usually avoided in Shmups by having a zone around the player, where enemies will not spawn and enemies will not shoot.
I'll give the demo some more playtime in the future and add anything else that I think sticks out. :)