I had a lot of fun playing it. It has many good points like art, music, gameplay but in order to give feedback I will focus on where I think it can be improved:
- Remove the energy counter on the surface, just keep the orb counter. At first I thought I could keep the energy collected somehow and after a few runs I realized that it always restarted. I think this small change would avoid generating the idea that you can save energy between runs (although you can save energy between runs with the upgrade the player would be able to see the energy he conserved when entering the first room).
- When buying all the permanent upgrades the orbs lose all purpose. My suggestion would be to add the possibility to exchange them for energy or items.
- -When you kill all the enemies and you have to wait for the remaining attacks to hit the wall to continue you lose a bit the fast pace. My suggestion would be that the doors open if there are no more enemies, so the remaining attacks can still hit the player but being able to continue without waiting.
- Personally the room that is a narrow rectangle is frustrating, especially when there was one of the enemies that counter attacks when you kill him. My suggestion would be to not add too narrow rooms or to balance the monsters that appear in them.
- Sometimes when trying to dodge it sticks to the wall when you don't want it to. My suggestion would be to only stick to the wall if you do it in combination with another button, though maybe I just need to get more used to that behavior.
- The weapons are a bit unbalanced. This is especially visible with the flamethrower to the point of avoiding using it.
That's all.. Even if is an alpha version it feels like a complete game, I can't wait to see the final version!