The two above methods have been patched.
You still get 3 game types in customs with 1 controller - Load up Oddball, CTF & Territories - Go to settings and select the score to win to its lowest possible option, load the game & get the win.
NOTE: For CTF - If playing with one controller - Go to settings & set the flag to "One Neutral" flag. Otherwise, enemy flag wont spawn unless someone is on opposing team.
NOTE: As Stated by "SignatoryStar" - The 4th game type can be done SOLO in "King of the Hill."
For the 4th game type
you want "Slayer" (cant win it solo)
Either have a second controller or get a friend to join you in a custom game (while making the setting to lowest possible "score to win").
Another option is to join a Multi-Player game and play it thru.