Big fat battle is a pvp game on steam. It is a free to play party like game that has Team death match, kill confirm, High value target (bounty) and last team standing.
This game is so much fun but can be a challenge. In a way it is kind of like stumble guys and fall guys and those kind of party games but you get to choose weapons.
Each character has a different hit box so when you pick your character be mindful of that. It shows up in the box with the name and their stats.
To unlock more characters all you have to do is play the game and level up. This is also how you unlock weapons and more.