Hi. For some reason, the game (not on itchio, but on the official site thing) won't let me upgrade the core beyond 2950. The button thing just isn't there. It's gone. This also happens with the wood and cocoa generator (before it can get to 100, the upgrade button disappears). Normally, I would assume it's the maximum, but since Jack (the sun) can do at least 3,000 damage, I pretty sure it's not.