If this is the game
http://www.youtube.com/watch?v=zDnyGnixNukit looks like it plays more like an old side-scroller arcade game than either an adventure game or what we usually think of as an action game. Closer to Mario than Syberia.
This is the game (more enjoyable without that kid talking in the background)
However, you don't spend your time jumping on mushrooms and evil creatures like in Mario, but most of the game is about thinking and trying out solution to brilliant puzzles, many of which include good timing but mostly thinking.
Neither Myst nor Dear Esther nor Uru nor Machinarium play like Syberia and we still call them adventures. What makes this game a border case isn't that side-scroller but the whole jumping thing. Uru has it too, nobody would argue about it being an adventure. It isn't as fundamental in URU, yes - but that's why I said this game is a border case.
In any way, I do not play anything but adventures but open my mind to twists of the genre, I'm sure a lot of players are like me.
I only got to hear of the game because it was under "adventure" in Steam (apparently they think it is one). I then checked it out, saw what it's about, said "let's give a go" and the rest is history. Like I've said, I would really hate to miss out on this game - so I'm writing this for the sake of other adventure gamers who aren't afraid of "dark" twists to the genre. I mentioned it's obviously not for everyone but timed sequences and jumping don't disturb everyone.
Is this a good thing that I should welcome with open arms? It shows the spirit of innovation? Even if it does make classification nearly impossible?
Sorry, just saw your question.
I definitely think we should welcome it, can't see what's wrong with it. If you mean to imply less point and clicks are being made because of that, I don't think that's correct.
Classifying isn't always necessarily. My favorite films tend to be a mixture of genres as well. Just saying "Drama" sounds so cheap sometimes - when it can contain so much more.
I just think it's important to mention what the game contains - and then let the player decide. We know that it can get really bothersome to try and define adventures... no one really succeeded doing that. Sometimes it's obvious they aren't adventures. I noticed Ron Gilbert said that for him Limbo wasn't an adventure. For me it was. It's obviously debatable - the fact that he referred to this game comes to show it's in debate.
but to answer your question - yes, I think we should welcome it :-) Don't have to play it though!