Overall a fun experience. I think basing the rank on time is a bit of a strange choice, especially since it is a bit of a pain to erase conveyors. I would have preferred unlimited conveyors and bombs and the ranking based on finding the optimal path with fewest bombs/conveyors used.
hey, thank you for trying the demo out, and for your feedback!
to be completely transparent, the ranking system is incomplete. we've considered giving unlimited economy (or at least make only bridges cost watts) but still haven't really narrowed down which direction we ultimately should go. once we iron that out, though, the rankings will 100% be redone, and also clearly telegraph its reasons for grading which it doesn't currently do.
again, thank you for giving it a go, your feedback, and kindness!