This is really well done. Great pacing.
I did encounter a crash when opening the first chest in the thieves' cave. You can jump up and squeeze through and on opening to get to the chest.
The error is :
############################################################################################ ERROR in action number 1 of Other Event: User Defined 15 for object obj_chest: Creating instance for non-existing object: -4 at gml_Object_obj_chest_Other_25 ############################################################################################ gml_Object_obj_chest_Other_25 (line -1) gml_Object_obj_interactive_Step_0 (line -1)