If you were using Flash IDE and wrote the game on the timeline, it would take the same amount or fewer lines, since a good third or more of the code is graphics

If you were using Flash IDE and wrote the game on the timeline, it would take the same amount or fewer lines, since a good third or more of the code is graphics and anim-related stuff that would be done entirely in the tool. As the other guys are saying, if we're talking about a bigger game, libraries and frameworks can provide substantial savings since they help you build consistent behavior across the whole app. But you can build those for Flash, too. I'm building one. It lets you iterate over the assets while the game runs and then ship a preloader by running a different compile script; it has user setting abstractions for keyboard, mouse, and sound, it has bitmapped font support, an entity model, some limited-but-growing tilemap and spritesheet abilities, pathfinding...in the next few days I'm planning to build out a menu system that I can reuse or customize for every game. In any case, these things are considerably more game-specific, and they provide an LOC savings that matters even on "weekend projects" - everyone likes to have user settings, everyone likes having a sprite sheet pipeline, etc. But you don't get that from a web framework used as a game platform, which is what this is.