According to this site http://www.firstwriter.com/copyright/symbol.shtml, you only have to register to use ®.
That's correct, it's why I put (registered) in parenthesis. He uses ® too in a lot of places.
However, even if
TetriBattle3 100%™ isn't a registered trademark and thus it's legal to use ™, it's certainly not legal to use a name so similar to
Tetris which is a registered trademark of
The Tetris Company LLC, who, according to Wikipedia,
"have vigorously policed and enforced their rights and have sent cease-and-desist letters to websites that infringe Tetris":Due to the popularity of Tetris, there have also been many knock-off and lookalike games on the Internet. In order to stop this infringement, The Tetris Company and Tetris Holding have vigorously policed and enforced their rights and have sent cease-and-desist letters to websites that infringe Tetris.
I didn't say anything about the game being a Tetris clone, even, that's understandable for a beginner programmer to recreate. Just that he shouldn't use symbols he has no clue about what they mean. It's a very common newbie habit to tack ©, ® and ™ on every name because it makes them look "cool" and "professional" (ironically, it does the exact opposite).