There's a bug with the inventory. If you have no free slots available, any creations you make will disappear. For instance, I just added 100 feathers to 100 arrow shafts (with a stack of unfinished arrows already in inventory) and they didn't get added to the stack. I was able to work through making all 100, though.
HP is completely broken for me. Max HP resets at some point before 10UDc, so monsters can do millions or billions times more damage than I can take almost immediately. By the time they make it to the base, they can do unspeakably more damage than I can take so it doesn't matter how much armor I have. A large chunk of the upgrades (and two towers) have been utterly useless to me since the very early game.
 "Quepland"){kind=icon}
 "Defender Idle 2"){kind=icon}
 "Porkin Hell"){kind=icon}
This will be fixed in the next update. Thanks for the heads up!