Oh I just realised the the book I’m using defines y as the vertical axis but in SRB2 z is the vertical axis

> looking for a new game
> ask the game store if the game is Z-up or Y-up
> they don't understand
> pull out illustrated diagram explaining what is Z-up and what is Y-up
> they laugh and say "it's a good game sir"
> buy the game
> it's Y-up