I've just played through the first chapter, not dealing with the character stories or skills, but so far I really just dig all the changes which have been made from TSE to the sequel.
I didn't play through TSE, but I enjoyed it a great lot when I played it, especially for how challenging and tactical it is. But I felt like the skill chain system, while a nice idea, wasn't really necessary or overly useful. Mostly I just switched the skills in the menu every time I needed a specific one. It seems as though this has changed, now that the combat really has gotten a lot deeper, with respawn timers, damage multipliers, enemies that can switch positions, etc. And also it's just become a lot more comfortable, being able to very freely assign the skill chains as you see fit, directly select skills, etc.
Technically it has also advanced noticably, although the handling still feels very similiar, apart from all the nice comfort options. Even though the animation isn't quite smooth I'm still liking the art, notably the character designs. And although I've basically come to expect it, wherefore it isn't really a surprise, the soundtrack is simply terrific. I'm unsure if I'll buy it, but I don't consider nearly 4 hours of quality catchy music for $16 to be costly :)
Lastly the story, which I only got a glimpse of, also seems interesting again, as well as the sweet character interactions. I just felt that there was a little too much focus on the "enfant terrible" kind of character, but it was just the first chapter, anyway.

So basically The Spirit Engine 2 seems to be all I hoped it would be and I guess for that price you can't go wrong with it. Unfortunately I think I won't buy it just yet, as I'm stuffed with games of all kinds I still haven't played through. But I guess TSE2 is a definite purchase for me nonetheless.

Some little remarks: I found it strange that you can control the entire game with only the mouse, but need to press the "Ctrl" key for running. I guess one shouldn't use it often, anyway, so as to not blindly run into enemy groups, but I guess a simple doubleclick mechanic would still serve it well.
Also I think it would be helpful to see exactly how a skill is being improved if you level it up. It may not be crucial, but I always like to compare how big the impact on a skill will be if I level up, so I can prioritise the ones which help me most at the time.
Finally I think each skill's name should be shown when you hover over them in the "ring menu" (right click on the character during combat). I'm surely going to memorise all the names when using them, but I'm unsure how much I will care about the individual logos, so showing the names would help.

Played the demo, and it's no "The Demon Rush".

Which means I'll probably end up buying this game. Still never finished the first TSE, though.

I'll probably skip this. Wasn't a big fan of the first game. Graphically this looks superb and a real work of art but the gameplay is too tedious and grinding.

WHY DO YOU TORTURE ME

Thanks for the news post Tim, and so quickly too! ( less than 30 minutes after I put it on my frontpage )

As I mentioned in my release post, cutting the demo has been tricky because the first two chapters are largely introductory and the weakest in the game.
I was a little cautious about not 'doing a Descent' and including too much though.

It's useful to hear all the feedback, good and bad, and I hope to address some of it in future patches. Though updating multi-frame applications in MMF is a real test of patience. ;_;

This being the sequel to seriously my favorite game ever, I picked it up right away. I'm playing on easy first since the story is the most compelling part. I'm on the seventh chapter right now and seriously, well done, Mark. It took a little while to get used to the new battle system, but the learning curve is worth the effort in terms of fluid gameplay. The music is rockin' too.

Should I play the first game before trying this?

Well, only playing the demo, I'm greatly impressed. The gameplay on normal is difficult, which I like. But, the bread winner is the story/character interaction. I love how my party talks to one another and I may consider buying the game. I don't have much money right now, but that will change in a couple of days.

Unfortunetally, I'm going to have to pick between this and a couple of other games I've been meaning to get...

Anonymous: You can skip the first Spirit Engine game if you'd like, TSE2 is a complete package all by itself, and it's a lot easier to get into than the first one.

Re: Your first little remark.
You can run with the mouse too. Just click closer to the edge of the screen. :)