personally theres alot of things i would like 2 c
1)biggger map
2)different maps
3)different kinds of zombies like a boss one idk
4)perks in the mode
5)xp
6)choose any gun u want instead of getting a random one in the toybox (of course the better the gun the more u would have 2 pay)
7)more special bomb things( eg: time freeze for 30 seconds)

every single gun from multiplayer in it (eg: ppsh)
9) special rewards if u were the only oneleft and u fended off all of the zombies
10) no glitches
thats all i can come up with for now