I cant install sdl because it has unmet dependencies
Try this one:
sudo apt-get install libsdl1.2-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libpulse-dev libxt-dev
If that doesn't work you may use aptitude:
sudo apt-get install aptitude
sudo aptitude install libsdl1.2-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libpulse-dev libxt-dev