Is it possible to Airdrop/Transfer Steam games to another computer?
Solution 1:
It is possible to manually install files for Steam games rather than download the game from Steam. Copy the files to this location, replacing (username) with your username:
/Users/(username)/Library/Application Support/Steam/SteamApps/common/Counter-Strike
However, you still need to log into Steam to play. There is no way around that.