1) Please let me move in eight directions, not just four. That's just ridiculous. (Landstalker)
2) Since you're making me roam in a perspective with additional and potentially confusing depth, please don't have me slide around like an ice skater. (Sonic 3D Blast)
3) Please don't shove platforming in an isometric game. (Landstalker, Sonic 3D Blast)
4) If you break rule 3, please provide shadows under sprites so I know where things are on the X (east-west) and Y (north-south) axes. There is a friggin' Z axis now (height), you know. (Landstalker)
5) In fact, pleasedon't make any isometric game that requires precision jumping. (Landstalker, Sonic 3D Blast)
6) Please don't put passages or people behind isometric walls where you can't see them unless either you indicate their existence or they are supposed to be secrets. (Landstalker, Sonic 3D Blast)
7) If you're going to break rules 1 - 6, please at least be a halfway decent game otherwise, like Landstalker. (Sonic 3D Blast)
8 ) Why do you exist? (Sonic 3D Blast)