Compressing sprite textures

I'm working on a game that is going to use a large number of textures, and I did the math. If we go through with our current plans the textures alone are going to take up over 30GBs. This is really extreme for a 2D game, and will probably discourage most from downloading it.

I was wondering if there was a way to compress my art assets and create a temporary folder at run-time and extract them for the current level, and delete them once the level is done? As of right now my stand alone version of the game stands at over 200MBs, while the web version is less than 8MBs. Any help will be highly appreciated.