.GB1 File Extension
File TypeGame Maker Backup File
What is a GB1 file?
Backup of a game project created with GameMaker, a game development program; created in case the original project file becomes corrupted or is accidentally deleted.
The number of backup files created by GameMaker can be selected by opening the Preferences within the GameMaker program and selecting the "General" tab. Then type the number of backups you would like saved next to "Maximal number of backups."