I had a lot of fun with the unique mechanics, like POWER RANGERS!
Unfortunately I crashed on the boss level when I tried to combine too close to the edge, I got the "Not enough room" error and then got this crash code;
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ERROR in
action number 1
of Step Event2
for object obj_boss:
Unable to find instance for object index 101396
at gml_Object_obj_boss_Step_2
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gml_Object_obj_boss_Step_2 (line -1)