Hey. Here's a quick little resource for you - it's a Display Preloader for your BGE runtimes.
This method allows you to start your game with specific settings - in this case, it disables mip-mapping on your runtimes. There are issues, though - this method requires the game to completely restart to work. Also, this method, for whatever reason, won't work on Multi-texture mode - just Texture Face and GLSL mode.
The process is packed into a blend file so that you can integrate it into your projects easily - all you have to do is append the preloader scene into your game, ensure that it's the first scene in the game, and create a runtime.
Anyway, here's the download.
Mirror 1: MediaFire
Mirror 2: FreeDrive