To start off, this game looks amazing. I love the progression between the builds, and I think it works seamlessly in a way I didn't think was possible. I think the game definitely fits in with the theme.
When it comes to the gameplay, I'm really torn. While I understand that the gameplay was intentionally bad at the start, it didn't make it any less frustrating when I was playing the game. As much as I like the idea of the game gradually improving, I had to grind through the first parts of the game, in order to get to the final build. I think if you were to make this into a fully fledged game, you still need to make the early builds enjoyable, as it could otherwise turn people off at the gate. I only managed to complete the game on my second playthrough, and I didn't even get to the final build the first time.
Overall though, you certainly achieved your goal here, and I'm amazed you managed to do all this in 3 days. Well done!