"Genre Breaking" games?

[jeebortjoobert]

What games can you think of that feel like they break boundaries and whose mechanics and vibes felt really unique to you? games you feel like you need a PowerPoint presentation to explain the premise of? for me it's "Knights in the Nightmare", I was gushing about it to a friend recently and was having a really hard time describing its mechanics, it feels closest to "bullet hell" but that really doesn't feel like doing it justice

 

[Bakuma1997]

Undertale, i've played so many RPG's where you play a minigame to increase or decrease damage effects, but nothing prepared me for a friggin shump like combat fest

 

[ArchienineZXAdventArchienineZXAdvent's icon]

I think Mega Man Battle Network