Too long for an intro and it ends abruptly.
It feel a good length but like a lot if anime openings have I’d recommend maybe adding a shot to sorta transition into the group shot at the end. As it is now the stop motion is good though personally I’d try maybe some editing softwear or maybe even build sets to use in the opening and the series.
Good advice… though with how I animate, using stop motion studio pro, all I can do is draw in effects and use green screen
Then do that. A change in brackgrounf never hurt anything,