Such a fun game, and I love the manual!
1) I finished with the artifact with 5 extra keys. I *think* this is the most you can have. I understand the 5+ key buffer gives you some lee-way, but the gate could have had a perfect run requirement and still not be too challenging.
2) Especially towards the end, there were some random red locked doors in the corners that didn't seem to do anything. (Perhaps they're just a key stash to prepare for grabbors?)
3) When holding left/right/up/or down, Zana moves one space, stops, and continues in a line. Movement would feel more smooth if Zana always moved uninterrupted when holding a directional key.
Overall, great puzzles and artwork. I would definitely play more