Ok the memory usage is almost entirely caused by these characters you've got underneath the level that are not really part of the level. Delete them. You've used the level as a kind of object bank but this should be in a different layout. They will need to be optimised in general though as one is spawned for the player.
Also they appear in the character select screen, consider using a different object for this - objects with one frame of the character. The tutorial is also approaching 1gb because of all the characters, they just need to be optimised I think each char adds about 200mb which is a lot when you consider that memory usage should be around 100mb max total for all graphics in the layout. This could work on mobile if you reduce those characters down.