Originally I had a list of potential ideas or things to explore, but after my first completion you seem to have answered most of them.
- I'm not sure if this is currently implemented, but the tree would feel a bit more cohesive with weight towards certain types of talents. Potentially could be done with leaves or travel pathways having a higher chance of being cohesive (at least to start out).
- Having chance opportunities are always exciting, maybe have the legendary nodes always visible, maybe the rare nodes are visible at slightly larger distances than just the normal talents.
- Potentially tuning up difficulty mid-run. Maybe you can take on an additional enemy trait for exp bonus/extra talent/something else of value. This could either be at important increments (5,10,15) or on damage-less stages. These could also be permanent or just for the stage.
- I didn't see a way to reorganize the 1-4 keys. Minor inconvenience.
- For some of the more complex stats, it is hard to know whether they stack, or how much the value is up to.
From coming in completely blind just to test, I sat through a whole run decently entertained. Great job!