Ah, finally. Been looking forward to this game a lot, evver since I first heard of it.
I was a big fan of the original Giana Sisters on the C64, but mostly enjoyed the Amiga version because of the improved music and graphics. (Still love the C64 music though)
Been planning on buying this game to support the developers, which you should if you really enjoy it and the old classic. Let's hope that Mr. Wallet allows it though.
Another game that I'm following closely is the Gianas Return homebrew project here:
http://gianas-return.de/
Been keeping an eye on that one for two years or so, long before the DS game was even announced.
It should be released soon, they're almost done from what I've heard.
It reminds more of the original game style, and I like the music a lot from the trailer I saw on youtube.
Will see a GP2X version, heard of GBA, I think a windows and linux build will follow and a PSP version was originally planned, but was cancelled after the DS game was announced.
(They do not want to compete with modern platforms now that Giana is commercially alive again.)
OLD OLD OLD Gameplay video:
http://www.youtube.com/watch?v=UgM7uDJNDt0