In order to emerge supertux there seems to be no specific need for USE-flags. Supertux installs fine together with the sdl-image library. If you actualy plans to run Supertux you have to emerge sdl-image with the use-flags JPEG and PNG set. In the bug-request 109965 it is mentioned that there might be a need of some USE-flags in order to get sound in Supertux. When building GTK the ebuild checks that dependences are emerged with the X useflag set so it should be possible. // Erik
lots of stuff could have lots of code added to do lots of checking. we'll fix it with use deps when the package manager supports it. In the meantime, use common sense on the use flags.
bugzilla
added use-based deps.