"GameDay Mayhem!!" is designed for shared-keyboard gameplay, allowing two players to play on a single keyboard (although, if you have two gamepads, feel free to use them, though this is less common among Windows players). However, not all keyboards support this functionality due to a limit on the number of buttons that can be pressed and recognized simultaneously. Only a few keyboards offer "n-key rollover," meaning they can theoretically detect all keys being pressed at once. 

In my testing, most keyboards were able to detect beyond 5 keys simultaneously, allowing smooth gameplay. To check if your keyboard supports shared play, you can use the following online tool: Microsoft Anti-Ghosting Demo. 

It's essential to note that there isn't a strict hard limit on the number of keys recognized simultaneously because different sets of keys are managed by different controllers. For instance, modifier keys like shift and ctrl are meant to be pressed simultaneously and thus counted separately. Therefore, it's recommended to test the specific keys relevant to the game you want to play. 

For my game, the key configurations are as follows: 

Directional Input: 
WASD and Arrows. 

Press 2 of each direction set to test diagonal input.

Actions: 
F, T, L, O. 

Press 2 of those action buttons since each player can use only one action at a time. If the ghosting demo recognizes 6 keys, your keyboard is compatible. If not, I've provided an alternative set of action keys: 

Actions: 
Right Shift, Right CTRL, Left Shift, Left Enter. 

Try this alternative set to see if you can reach 6 keys, and you should be good to go and have fun!