To get the special games you must graduate in Academy mode and also get all three Specter Coins behind any of the three panels.
||How to Unlock
|Every Monkey's Golf
Snowkidz Snowboarding mini-game:
Get 10 Specter Emblems.
Specter Boxing mini-game:
Get 20 Specter Emblems.
Jake Attacks mini-game:
Get 30 Specter Emblems.
Ape Ping-Pong mini-game:
Get 40 Specter Emblems.
Extra Ape Ping-Pong characters:
Beat the Ape Ping-Pong mini-game.
Extra Specter Boxing characters and Survival mode:
Beat the Specter boxing mini-game.
Thanks to Revolution reader Cyr and BOMBA!