I know some of these are not exactly "boss fights" and more of a "run away from the boss" parts, but I thought I should include it anyway.

Ori and the Will of the Wisps on Steam: https://store.steampowered.com/app/10...

Difficulty: Hard (3/3)

Bosses in video:

[00:00] 1. Howl
[01:01] 2. Horn Beetle
[02:18] 3. Watermill Escape
[03:53] 4. Mora
[08:26] 5. Kwolok
[14:03] 6. Avalanche Escape
[15:46] 7. Ruins Escape
[18:37] 8. Willow Stone
[19:25] 9. Shriek

[26:28] Ending

At the very first fight, it looks like I'm getting hit while running from the boss, but it's supposed to happen and you don't take any damage.

This game is not free of bugs. For example, when you escape from the final boss, you always take damage while digging through the sand. It's clearly not intended, but thankfully you can go around it and stay unharmed. There's also another part there which damages you for no reason, but that one rarely happens.