I always chuckle at the Hollow Knight comparisons. I honestly didn't look at it that much, I never even finished Hollow Knight since I didn't like the pacing of the game all that much. It took me 20 or so hours there to find the doubleJump and at that point I just kinda lost interest. But hey, that's me, I still thought it was a very good game.
But the fact of the matter is that we wanted to have attacks like in WotW in Blind Forest already, but just never got it feel right back then. Our Animator at the time, James Benson, did some anims in like 2011 or so where we had Ori swing a sword and tried to time the attacks to Symphony of the NIght (Symphony of the Night, Zelda and Super Metroid were the main inspirations in terms of Game Design), but it just felt wrong and since we didn't have all the money in the world, we decided to re-pivot for Blind Forest and focus on the heavy platforming-focus, cause that felt great right from the start. For Will of the Wisps, we had a larger budget and knew that we finally had the resources to delve deep into the combat mechanics.
The Spirit Shard system though was indeed inspired by another game, but also not HK: Initially I wanted to copy the FFVII Materia system since I LOOOOVE that system and I still fully intend on using a variation of that system for another game :D In the early WotW prototypes, every weapon / spell had slots and you were able to slot the shards into them, but that just became too complicated for an Ori game. We didn't want people to spend that much time in menus after all - So we just turned it into a global system and kept the leveling part of it.
I think Hollow Knight and Ori honestly both have their own thing going on, I don't really see all that much overlap apart from them being both Metroidvanias. The way we design levels and our world is completely different from what those folks did. Our game is all about movement, Hollow Knight is way slower and less focused on flow. It's like comparing Mario and Sonic to me - Sure, both are platformers, but that's where the similarities end. I'm just glad we're seeing more amazing Metroidvanias finally again, since when we started Ori there was absolutely nothing like that for the past 15+ years or so. Super Metroid and SOTN came out and suddenly everyone decided that that style of game wasn't worth it anymore, which was always nuts to me, ESPECIALLY since the Igavanias always had super high ratings.
But anyway, there's your inside scoop :)
