Wow, my first time getting to the strange red eye was a really cool moment. I loved the dialogue of the red eye so much, it was so foreboding and so at-odds with the upbeat feeling of the game so far. It felt like such a genuinely mysterious moment.
I wasn't sure if I'd be able to do it, but I got all the upgrades! Is the game supposed to end after this? I got to the red thing with full upgrades and it just told me to leave.
This was surprisingly addictive and very elegantly simple!