When you upload your game to Thrungames you still own the game. But Thrungames have license to use it. If you upload a game with copyrighted material you will get a strike. If you get too many strikes your account will be terminated.
Do you have copyrighted on Thrungames and want to keep other users from stealing your material. Here at Thrungames we try our best at preventing that. But sometimes our algorithms miss things. Therefore if you see yours or others copyrighted material please report it and we will take care of it.