Slither.io multiplayer game development -- 2

I need a game app developer to optimise my game app for cross-app ios, andriod and web format. The game was build in unity, its multiplayer and similar to slither.io and worm.io. The game is 50% completed, but the previous developer encountered technical issues which he could not resolved. The snake could not grow longer without it lagging and freezing and when multiplayer come into the game, the snake graphic of the new player is broken and not smooth.

Only bid for this project if you have coding expertise in this area and can guarantee successful development. APK is available to review Project price can be negotiable.