As it says in the auction, it's a "doujin" (fan-made) soundtrack CD for an imaginitive new Raiden game for GBA. The music was made using the GBA's sound chip. The game itself doesn't exist, it's entirely fictional.
But yes, it does appear to be a tate shmup; if I interpret the page correctly, it just came out a couple of days ago. Wonder where the "15" age rating (if that's what it is) came from though...? Looks like it borrows a lot from Raiden.
EDIT: Guess I'd best leave the interpretation of this to people who can actually read Japanese, heh.
There is a real tate GBA game, though. Atari Anniversary Advance has tate for Tempest, Super Breakout, and Centipede. The new Namco Museum 50th anniversary collection coming out for GBA will also have tate.
But yes, it does appear to be a tate shmup; if I interpret the page correctly, it just came out a couple of days ago. Wonder where the "15" age rating (if that's what it is) came from though...? Looks like it borrows a lot from Raiden.
Actually the link is just for the soundtrack too. As I said the game is entirely fictional, the screenshots are just fakes. What the makers of the CD would imagine a GBA Raiden to look like if it really existed.