So, you thought that HAVE Online, that Korean Team Fortress 2 with Haruhi Suzumiya was blatant in its inspiration enough?
The days of the Great Giana Sisters may be long gone (barring that DS game of theirs), but those wacky Chinese succeeded them with the single most blatant 3D Mario clone ever here in 2009, and its name is not Auditore (Don't you remember him, Ezio?), it's Duludubi Star; an extremely obvious copy of Mario Galaxy.
This video shows the first four levels of the game. Just sit back and take notes.
Oh, and they also stole Klonoa's voice.
And if you really must, experience the clone right here: