Fact1 you can use any key despite the tutorial saying yellow key fact2 more than 1 glitch key can be spawned in the same game and multiple people can put it in the tp chamber you just have to wait fact3 you can use 1 key per person to spawn the key(if a player used a key on the blue door they can’t spawn anymore glitch keys using that key or by that player)
I got the badge today (Including The Prototype skin) it took me 3 attempts to do the mall then 2 attempts to do the plant step. (Did this with my skilled friends).