I've been enjoying video games for most of my life, and some of them come with a seizure warning before I start playing. This is to make sure that people who are prone to seizures or headaches know that there is a large amount of strobe effects in the game they're about to start.
I've never felt that been susceptible to the problems the warnings are meant to address, but then again, I hadn't played Beat Hazard Ultra, either.
Beast Hazard Ultra is a shoot-em-up game that uses your music to generate levels. Gameplay-wise, it's a mix of Asteroids and the traditional two-joystick shooters that many players are already familiar with.