This is a really fun play on tone and atmosphere, somehow being able to merge many things: an arcade-style collection game, a horror game, and a sort of interactive fiction segment at the end. I like how you committed to the bait-and-switch in a Frog Fractions way. That playfulness is very fun.
I guess I have to assess the tone of the game on two levels. The bright, happy Dreamcast vibes are on point. The breakbeat soundtracks, playful Mario Sunshine -esque (?) fonts and the low-poly colourful textures really set the mood for the kind of game that you're evoking and is executed super well.
The horror aspect is a delight and you clearly had a lot of fun thinking about how to slowly subject the player to more eerie and strange environments, before bringing in the darker setting and using the narrative to introduce its concepts, before bringing the game to a really bizarre horror climax.
I think the only constructive criticism I'd add are that, although the lack of sound works for a time to support the darker mood, some ambience could have worked. The ending text is great, although the level of exposition is probably a little too excessive to really succinctly hammer home the story.
I did a playthrough of the game below:
This is really great. I hope you keep exploring games that deconstruct narratives and genres like this. They really stand out and they're a blast to play. Great work!- FSV