As opposed to most MOBA style games, increasing your health in Awesomenauts appears to be mostly reliant on buying specific health upgrades. Additionally, you purchase abilities (and upgrades) via money, not levels. In fact, nearly everything seems to be based on the amount of money that you've gained as opposed to character levels.
For example: since you can't (that I know of) see your actual HP numbers, there's no easy way to determine if the simple act of leveling up gives you any additional HP.
So I'm wondering what exactly happens when your character levels up (in a round)?