Are you only allowed to buy one of each upgrade? Because I had a ton of bones and empty upgrade slots after reloading my game, but it still wouldn't let me purchase two attack upgrades. I was only able to buy one attack, one defense, and one health.
Yea currently you can only buy 3 of 4 possible upgrades and only 1 of each, as the game grows i'll eventually added a more robust skills upgrade system,
