Xyzzygames, as this seems to be your first uploaded game, I congratulate you.
- simple, and elegant interface. Perhaps even a little too simplistic?
- there ARE noticeable differences with each item's upgrade, contrary to what other commenters have said. That said, they require a lot of upgrades to achieve, which becomes rapidly tedious.
- Spirit Boost button was a godsend.
- the planet's revolution is in one sole direction - as well as zooming in and out, it would be nice to be able to control the rotation. However that would bring into question the laws of physics...
- I would like to think the planet is not made up of infinite three-dimensional tessellations, but I understand how this would have been easier to create as opposed to smoothing every edge.
- where are the animals? Am I missing something?
- does this ever end?! What is its final form?!
Bonus points to you for pop culture (Hitchhiker's Guide To The Galaxy!) references. Good luck with your future projects!