Paper Mario: The Thousand-Year Door

Paper Mario: The Thousand-Year Door, released in Japan as Paper Mario RPG, is a console role-playing game developed by Intelligent Systems and published by Nintendo for the Nintendo GameCube. The Thousand-Year Door is the fourth game in the Mario RPG series and the second in the Paper Mario series.

Professor Frankly's Gate
The gate outside Professor Frankly's house turns into a cyan block, and then disappears when he is opening it to show you the Thousand-Year Door.

Punies
The Punies may display incorrectly on all backends. EFB to Texture displays garbage, while EFB to Ram shows the Punies but distorts them. It only happens when they are standing still, and seems to happen more when they are facing left and not right. See.

Cache Display Lists
Enabling Cache Display Lists causes bounding box glitches.

Sound Issues
DSP HLE may have audio crackling after extended play. Use DSP LLE to avoid this. Fixed by the merger of New-AX-HLE 2.0 in.