It is the 2nd anniversary game in the series and as such shares more similarities to "Puyo Puyo! 15th Anniversary" than "Puyo Puyo 7". This game came out 4 months before "Sonic Generations", which is also commemorating the 20th anniversary of the Sonic games.
There are 24 playable characters available, each with their own 8-stage course (similar to Puyo Puyo! 15th Anniversary).
This game, as it's predecessor, was released only in Japan.

It is the 2nd anniversary game in the series and as such shares more similarities to "Puyo Puyo! 15th Anniversary" than "Puyo Puyo 7". This game came out 4 months before "Sonic Generations", which is also commemorating the 20th anniversary of the Sonic games.
There are 24 playable characters available, each with their own 8-stage course (similar to Puyo Puyo! 15th Anniversary).
This game, as it's predecessor, was released only in Japan.