Also, an easy trick to the game is to dump all of your money into income and knights. Just keep upgrading your stables and blacksmith. Then upgrade your knights health and attack. Follow that and you have nothing to wait for by map level 34.
Got to level 100, all upgrades at 500. At around level 40 is when the game is basically automatic and not very idle like. So I figured when you could no longer see what an upgrade cost, that is "end game"
Nice game, a little short and I would have liked it if the shops were able to upgrade or an option to automatically install certain parts that you checked. Otherwise it was a nice little game to waste away on your break.