Initialize XIX, XIY, and XIZ to match what the BIOS leaves them as(as observed via MESS' debugger), and removed the ROM patches/hacks for "Puyo Pop".
Initialize VRAM differently to partially reflect the state the BIOS leaves it in, and removed the "Metal Slug - 2nd Mission" ROM patch/hack (thanks to "FluBBa" for the tip on what the game was doing/relied on).
Initialize XIX, XIY, and XIZ to match what the BIOS leaves them as(as observed via MESS' debugger), and removed the ROM patches/hacks for "Puyo Pop".
Initialize VRAM differently to partially reflect the state the BIOS leaves it in, and removed the "Metal Slug - 2nd Mission" ROM patch/hack (thanks to "FluBBa" for the tip on what the game was doing/relied on).