this could and should be two-player just amke it so 2nsd player uses the wasd/arrow keys to move and uses q and e to cycle through the troops you found (2nd player can only play if you have at least one troop) because that would both be really fun and also helpful on missions like kill 10 guys with grenadier
as an add on to what linty said if you effectively use cold snaps and sneak attack you can get tons of treasure i usually get about seven kills per enemy + so people can see
you should be able to get rid of old perks at the cost of a level so you can get new ones because i'd like to trade in one more and fast learner for something actually helpful when your fully leveled up