The present disclosure provides a system and method for updating a game application during runtime of a game application. The game application is executed on a client computing device using application code that includes a function store. During runtime of the game application, a function asset is received and stored in the function store. The function asset includes either precompiled code or code written in a scripting language and includes a version identifier. To execute a particular game function of the game application, the function asset is identified from other function assets in the function store based at least in part on its version identifier, and the game function is executed using the function asset.