That's awesome that this was made by a 12-year-old. Seriously impressive to put a full game together in a week. The theme was fun too, fighting off virus-style enemies inside the body is a cool idea. I like the music a lot; it gave the game a playful energy and fit the vibe well (shoutout to dad on that one).
The hook mech was a neat idea, and the gameplay felt solid overall. It's clear a lot of effort went into making all the assets from scratch. For a week-long project, especially at that age, this is something to be proud of. Keep making games, you're definitely on the right track.