Whoa. This is an underrated gem! Very impressive for just one month's work.
Firstly, it looks and sounds great. The main character is animated adorably. Each area is visually distinct, with a lot of personality, and has its own theme music with smooth transitions.
Secondly, exploring is full of choices and considerations. The map is chock-full of interesting decisions and bite-sized puzzles, and all the areas interconnect in multiple ways. And each time the player acquires a new traversal ability (crawl, wall jump, etc.), it really feels earned.
Thirdly, the flexible way in which enemies are used (to strike other enemies; to trip switches; to double jump...) is very clever, and leads to an additional layer of tactical decision making. (Most notably: "Where can I find a nearby enemy, and can I return to this spot without using it up?")
The game checks all the other standard boxes, too: The controls are responsive and smooth. The map is bare-bones but functional. The frequent interactions with other ghosts are usually helpful, sometimes amusing, never annoying.
I always like to offer some constructive criticism, but in this case it's hard to think of anything that needs improvement. I would say that there are some areas where not enough enemies spawn. This leads to a perverse incentive for the player to fall on spikes and die so that the enemies will respawn.