I came up with the idea of a duel currency system in the game I'm making, Coins and Gems, Coins will be used for in level stuff so more health and things like that, Gems will be for Player upgrades, so think double jump extra damage and so on. Gems will carry over from level to level but coins will not. But I plan to have a Coins to Gems conversion in the shop and the shop will hold your gems for you (I don't want to make a new UI this on is hard enough to work with 😂)