Here's a list of each game and the available game modes in GameBeef. Keep in mind that if a specific game mode is not in this list, then you won't be rewarded with money after playing it.
Dota 2 - only Ranked matches allowed
PUBG - both Normal and Competitive matches allowed
Age of Empires II
Age of Empires IV
StarCraft II - only Ranked matches allowed
Team Fortress 2 - both Casual and Competitive matches allowed