Thank you for the bug report! I'll see about figuring out a fix to that since that would be really annoying to complete ^^;
And I'll look at the investment bug since it could be a calculation error on my part. Though if you could double check for me, that it isn't already leveled with R. Z points reset after a run but R points do not so the stat could be leveled up, if I understand your description correctly.
I didn't try since then if the bug was fixed but here is the problem I had: example: I get 4R in run 1 and invest them to upgrade something 4 times (1R for each level), the 5th level is also indicated to be just 1R;
I complete run 2: instead of costing just 1R, the 5th level costs 4R (or 40Z) now; so reaching the 5th level cost a total of 8R; but if I reset the R, it would only cost 5R in total.
Basically, what I had was: if I invested R in an upgrade in a previous run, the next levels of this upgrade would cost the total of R already invested in it in the following runs instead of the normal cost.
I tested the bug multiple times and it always appeared