I never played the original but this gem makes me wish I had.
I never played the original "Bionic Commando," but after playing this and reading about how faithful this game is to its source material I sincerely wish I had.
(Upon beating it for the first time I absolutely had to look up the ending for the original on YouTube.)
The game is endlessly creative, the dialogue appears as if it came straight out of the first "Bionic Commando" (I found later that much of it did,) the visuals are great, especially the still artwork, and it's just damned fun.
If you are curious as to why it is rated "M" after playing the demo, you won't wonder when you get to the end. (Which is the only even moderately offensive bit in the entire game.) Don't worry about it too much though, I had built it up in my mind so much that when I got there it was still surprising but not as bad as I'd expected.
I would suggest this game to anyone and everyone. Even let your children play it, just don't let them fight the final boss. (I'd say don't let them play the final level as to try and not give too much away but the final level is the most brilliant thing in the entire game. Everyone should play it.)