Obscure music from videos games

[Tizm]

I found out that a kids game called: Mario Teaches Typing has a rap song built in it.
What other games have obscure music like this?

 

[EddieEddie90]

I found out that a kids game called: Mario Teaches Typing has a rap song built in it.
What other games have obscure music like this?

Define obscure. I think the weirdest find that I have seen is that in Sonic 06 you can hear a song from mega man 2, also in batman return of the joker for the gb you can hear like two songs from said game too.

 

[Tizm]

when I meant Obscure I meant music that you wouldn't expect in that game.

 

[EddieEddie90]

when I meant Obscure I meant music that you wouldn't expect in that game.

The Darius series have very weird songs sometimes.