Thank you for your kind words Aurélie. I really did experiment with many and all the little easter eggs and hidden secrets (like depending on which kind of upgrade you choose first, the narrator voice changes) - all the little things to make it a unique experience. That's what I want the whole game to feel like on full release. :)
Edit: Oh, and because you mentioned the audio design: I literally slapped together the music (which I fortunately already made) and audio system with most of the effects in the last hour before I had to build, upload and submit the game. I had some technical issues right before that, so it really threw me off and that's why it isn't quite as polished as it could've been. So I'm glad you still liked it. I'm shutting up now. :D