I'm not sure how Crossover works, but I take it it emulates the Windows OS? Once you have it running, go to the Batcap folder and double click the BattleCapacityV5_1.exe file.
Once the game is up, click W or S (up or down) to activate the cursor and select either Arcade mode or Versus.
Use Lunaport if you want to play online. Make sure the game is closed and open Lunaport, selecting the option you desire by typing in the number and hitting enter.