|Mount Horu, the last area of the game, has an incredible difficulty spike...|
There's fire and lava everywhere, and even most of the floors that you can stand on, will hurt you if you stand on them for more than like half a second. There's a bunch of really fast shooting enemies that can only be defeated by their own projectiles, and often you NEED their projectiles to get up through the paths, so you have to kinda avoid killing them.
At the top of this area, there's two doors that lead to some linear action/puzzle sections where you push a rock down to block the lava flows, and this opens up a couple more doors below... each door leads to more difficult action/puzzle sections that open up more of the Mount Horu area, until eventually you get to the bottom where you find the final element.
After beating this dungeon, you just get to the final chase sequence, and then the ending cutscene and credits... Kuro, the angry bird that chased Ori down and knocked him out, had a change of heart after seeing the black forest spirit character (who has been revived suddenly thanks to that 2-legged thing) take Ori in his arms... Kuro then sacrifices himself to revive the spirit tree, and the cutscene ends just as Kuro's egg is about to hatch, so you don't know whether that bird dies from the spirit tree's light or not. This ending was kinda dumb... I dunno, I wasn't feeling the whole emotional thing it was going for.
I found the map stone for Mount Horu, but I couldn't find the missing piece of it after exploring the entire area... also I never found the last of the blue energy cells. It's just nowhere on my map, even though I unlocked the ability to see where they are on the map. It's like my game is glitched or something?
Oh well, whatever, I completed hard mode with 99% item completion, and I didn't unlock all of the abilities on the ability tree. That last area was the perfect difficulty level and I'm kinda glad I didn't get the extra defense, or the latter half of the offensive ability branch cuz it would've made it a little too easy. Also I never got the see through fake walls ability either, that might've helped in finding the last map stone piece and the last energy cell I guess... but screw it, I'm not gonna scour the entire map again looking for that stuff.