Notes about the MW0 file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The MW0 file type is primarily associated with 'Super Mario World' by Nintendo. Super Mario World (commonly abbreviated SMW) is a platform game developed and published by Nintendo Co., Ltd. For the Super Famicom/Super Nintendo Entertainment System. ROM hackers will often use tools like Lunar Magic to edit levels or add new levels to the game. Version 1.60 of Lunar Magic uses only one .MWL file; prior versions required *.MWL, *.MW0, *.MW1, *.MW2, and *.MW3 files.