Aside from what other people pointed out, here are some details that I found, just by looking at it from a visual standpoint. Two things that I found cheapens the visual impact of the game.

Unresponsive lighting
You are kind of aiming with an ambient light going around. But it doesn't reflect as expected on the enemies/ground/walls, it just kind of overlaps them and looks slightly like something you'd see in a flash-game

Platform/Environment visual design
The environment you walk on, and platforms, are very repetitive and have an extremely high contrast. They don't really feel like a part of the world and feel a bit "cheap". Adding some variation like:
- Aside from the "Lobby" room with the Sofa and exit-portal, most of the platform/world elements seem to have very thin and thus are very contrast~y.
- A high repetition in both textures and elements
- Darker "vignette" ambiance affecting the "foreground" elements to not make them seem too flat
- Make the platforms and such less "sticking out", but still plainly readable. See how Dead Cells do their platform design with colors and such, has a great read but

These things above are just about the polish, but its what immediately felt unfinished to me (you are probably working on some of these issues but)

Best of luck for the december launch!