Very cool concept - and executed masterfully. The level of polish on this game is absolutely crazy, from the cutscenes between each level to the clean animations and snappy sound effects. The art is minimalistic, fitting, and extremely cohesive, building an extremely well-done atmosphere that perfectly embodies the theme of "Halloween" and "Parasite".
I didn't realize I could move until failing on the second level multiple times, but I think that was just an error on my part. Besides this, I think the instructions were quite clear and the gameplay was simple and intuitive.
The gameplay was fun at first, but got boring after a while. Perhaps, if you're planning to continue to update the game in the future, consider adding more elements to spice the earlier levels up. The action of jumping between humans and walking is interesting, but I think it could be expanded on for some really cool features.
I think the game fits "Uninvited Guest" really well - it's a unique take on the theme that's creative and imaginative. Perhaps, besides the spooky atmosphere, you could expand on the "Halloween" part of the theme as well. I see it, but it's not fully fleshed out.
Overall - a really solid entry that clearly showcases the talent of all the devs who worked on this. Even with a limited scope of time, your team managed to create a super creative, high-quality videogame. Great work!!