This was really satisfying to play once I got the hang of it! Initially I found the animation-lock of summoning my ghosty forme quite difficult to manage, but it definitely got easier with some kiting practice.
I also got a bit stumped on firing the gun, I got confused when I tapped the LMB and it didn't fire immediately, so I figured it had to be fully charged and collected my heart out, before finally having to scroll down to the controls section while frantically kiting around to realise what I was missing. Super simple fix with a tutorial/an animation/sound while the gun is revving up, and I only really bring it up 'cause it was funny! I only ended up needing about half my reserve in the end, but it never hurts to be prepared.
The art and animations are soo good, they really sold the aesthetic and made it fun to look around while exploring the level. The UI was super clean, and the menus were a nice touch.
It was really cool working out how to manage my time while beating back the horde, when to switch to my offensive but vulnerable state, how to create enough space to charge up the machines, even with just the two enemy types there was a good amount of variety, got me excited about future levels!
I can see you had a conversation on another comment about the ghost attack mechanics, definitely agree with your thoughts about considering opening it up to a 'combo' system of movement, although I do see why you didn't go with that initially as the power balance would be hard. It added a lot to feel like my back was constantly against the wall!
I really appreciated how simple you kept the controls, it's tempting to add too many hotkeys and leave the player a bit tangled, but having such a streamlined, contextual system worked really well once I was used to it.
Overall, really fun and brimming with potential; great work to everyone on the team!