If you really have trouble fighting your shadow, the solution is painfully simple. Stay on the same ledge and let yourself get hit for all his sword waves (try to get fortitude, hardy and healing as high as you can). Jump through his ranged fireballs. Avoid the ranged fireballs and you won't get hit by his laser if you stay on the ledge. He should be next to you, slamming you with sword attacks, when he uses his rock attacks. Jump to collect the black gems and repeat.
The shadow guy is hard but not unbeatable. He just takes too much less time and the only hard part is his last 25%. Please give him only that part.
The story came all in one bulk, and it was really fast and weird. But yeah, I suppose it checks up.
After the part with Kathryn, I was astonished to see it was nearly over; by the way, for the past few levels, you can just throw so many people over that eventually they will have to get to the other side :P
At the start of the tutorial, two invisible buttons popped up, so I clicked on the,.. Then, midway through, the entire thing started turning into a mess of invisible buttons. I was on the build screen and asked to build Centaurs..sigh