Currency is the only form of money in Flood Escape 2. There are two main types of money, coins and gems. The VIP gamepass, however, can be purchased only using Robux.
Coins are the normal currency that you can obtain with Robux or just playing the game.
Gems are a special currency that you can obtain by buying them with ROBUX, leveling up or playing normally if you have the VIP gamepass.
Each level up will award you with 5 gems.
The maximum gems you can get from leveling up is 495 gems.
You can use Gems to change the next 3 maps into insane maps for the cost of 10 Gems (Note: Insane maps are selected randomly, not picked by the player who locked the lift) or buy Tanks, Buddies, Emotes, Skins, and Auras.