Heeey, yeah we struggled a bit to make it feel like a finished game. Cool thing that you noticed spawn moving, yeah, that's something I though of would be cool, among other level design tricks. Unfortunately didn't have enough time to make levels to use all of them.
Regarding controls and physics - its janky, made just to work reliably enough for the demo. Jump height can differ depending on how you move before that, or if corpse gives you acceleration beforehand, either way, as you rightly noticed its inconsistent and will be reworked if we were to work on game further.
Glad you had fun and thanks for playing!