here's my big game called fish.io try it out

NOTICE: This game was not made by OP. This is a stolen game from SmileBASICSource called Food Chain.

does it support local multiplayer

not yet

It probably never will, since Dallas did not change any of the code whatsoever and most likely does not understand UltraPheonix4's code. It is not a multiplayer game in any aspect, and does not fit the .io category.