A lot or a little?
Parents need to know that Heavy Metal Tennis Training is arcade tennis game for iOS and Android devices. Players use simple touch controls to hit a flaming tennis ball, hopefully back at the ball machine that shot it at you. But while those fiery balls will burn your character to ash if you get hit with one, the game's old school graphics mean this has no blood or gore. It also has no objectionable content. Commercially, though, you can spend real money to have unlimited lives or to play with such characters as "Uzzy" and "Queen Hellizabeth" if you don't feel like playing enough to unlock them. Read the developer's privacy policy for details on how your (or your kids') information is collected, used, and shared, and any choices you may have in the matter, and note that privacy policies and terms of service frequently change.