Overall:
The core gameplay is known from tower-defense games and it’s fun! I find the idea itself innovative, and I really like the presentation. At the beginning I expected something more like a horror game, but the game stayed rather cute in my opinion. The upgrade functions add a lot to the game — although the balancing could use some polish. I had no issues, but some upgrades felt unnecessary. For example, Damage Upgrade 2 and 4+. At first you defeat enemies with 3 shots, then with 2 after the upgrade. With the next upgrade, it stays at two shots (which is a bit frustrating and unnecessary since there is only one enemy type). With the third upgrade, enemies finally become a one-shot (very strong!) — and further upgrades then become unnecessary since you already one-shot everything.
Still, the game is fun, and the short intro is very motivating. I could imagine this game working excellently as a horror game as well (jumpscares, more enemy types, droning ambience instead of music, different enemy movement patterns…). I think it’s a very good foundation to build upon.
Graphics:
Simple but functional low-poly 3D graphics with bright colors — fitting for the theme. The UI (button colors, layout) could be improved a bit. Using a consistent color palette for the UI would be helpful — for example by looking at Lowspec palettes. Also I would suggest using another font - maybe a bit more playful so it fits the children's room theme.
Music:
The music supports the distinction between the two gameplay phases. The sound effects work well. I could imagine a droning ambience working even better for the night phase.
Theme:
Very well implemented!
Conclusion:
A simple tower-defense game in a unique setting — with a lot of potential for becoming a horror game in my eyes. A really solid entry!