Theme: Not horror per se, but adhering to the horrific creatures trope
Fun: There is an interesting idea in here, but it's not well explained and the game is probably not finished fully. For what it's worth, feeding tiny monsters meat is a fun concept. I don't know why I died (probably the red one was eating me), so some feedback like a healthbar would go a long way.
Game Design: The game could use a bunch of sounds, maybe some ambiance. Main character didn't have animations, but the creepy crawlies' ones were pretty cute. This is a neat concept and I'd like to see it more realised, as I'm a fan of taking care of pets in games like these. The monsters changing in unpredictable ways is a great mechanic - being able to dispose of the undesirables would make this more interesting and give players a choice between keeping his tiny horrors alive and keeping himself alive.