The Smurfs 2

85A57E: LDA $002140
85A582: CMP #$bbaa
85A585: BNE 85a5b7 ($30) <- ???

Enables some intense DMA transfers then checks sound port 0x2140, if it isn't 0xbbaa then it goes to an alternative route instead of just recheck the sound port. Timing bug.

Man, SNES programming tools must've been very very very ... very dire --"