Games with hidden/hacked multiplayer?

[HappehLemons]

Wondering what games out there are advertised as single player games, but have some kind of multiplayer aspect to them or some kind of multiplayer hacked into it? Off the top of my head I can think of..

Way Of The Samurai 1 for PS2, had a secret code for 2 player versus mode. Said on the back of the game it was singleplayer.
Super Mario 64 recently got an awesome 2 player hack.
Banjo Tooie had bottle revenge gameshark code where the 2nd player could control all the enemies.

[o.pwuaioc]

There's a hack for Seiken Densetsu 3 to allow for 3 players.

http://www.romhacking.net/hacks/179/

[Urzu402]

I know this isn't Classic but the PC version of GTA San Andreas, has a Multiplayer Mod for it, that is quite good.

[BricatSegaFan]

Megaman 7 had a hidden vs mode.


https://www.youtube.com/watch?v=TJQnUtk0no4&feature=youtube_gdata_player

[SOL BADGUY]

When you load Banjo Tooie in Project64 and go to cheats it lists a "Beta Bottles Revenge Mode" and it says


Bottles Revenge is a Beta mode from Banjo Tooie that the RWP team recently uncovered after an extraordinary amount of effort. Bottles the Spirit transforms into Bottles the Devil and posses enemies nearby and allows a second player hooked up to Pad 2 to play as that Posses character to try to foil Banjos Plans. As player one goes about its business, player two uses every enemy nearby to try to nab Banjo and take away some life. This mode is incredible, and you can control almost every enemy in the game: slot machines, flying creatures, uggers, zubbas...and this is just the beginning. (Congrats Rare Witch Project)

Oh shoot, missed it up there in the OP. :S

[Smashed Brother]

Tempest X3 on the PS1 had a hidden 2-player cooperative mode that could only be accessed by getting the high score and entering a specific code. But I don't think that it was properly finished because the second player doesn't respond to controller input whatsoever.

[Xander]

There's a hack for Seiken Densetsu 3 to allow for 3 players.

http://www.romhacking.net/hacks/179/

In the same vein there is a hack for 2-player mode on Secret of Evermore

http://www.romhacking.net/hacks/24/

[xelement5x]

In the "kind of but not really" category there is Zero Tolerance for the Genesis.

It came with a multiplayer mode that would only work with a custom cable, but the cable was only able to be purchased if you sent in a coupon and bought it directly from the publisher. There are not a lot of them out there, there so the "hack" is that you can make your own cable to do the same thing and get multiplayer working.

[Collector_Gaming]

I don't remember if it secretly hinted at it in the manual or not but duck hunt as we all know had some form of multiplayer (you can control the ducks with the second controller).
or did this topic idea sore over my head as everyones listing hacks which this isn't... Just a un advertised feature.