I pretty much finished the current build of the game, and had quite a bit of fun doing it! The one thing that I noticed was that as I went up the tree tiers, the spawn button seemed to refresh slower and slower, at tree tier 1, it refreshed in a little over a second, but now at max tier, it seems to refresh in a little over 4 seconds. Was this intentional? It makes it a little difficult in certain tiers to outpace your felling speed, even in the mid to late stages.