These physics aren't necessarily what you'd expect. Acceleration is gained easily and preserved, especially when jumping. You cannot dash down, but you can still do actions involving it. In other words, Celeste w/ Swiftness IV.
Required tech: Wallslides (walljumping after dashing upwards) Superneutrals (wallslide then holding in the direction of the wall) Wavedashes (dash down-left or down-right then jump left or right, respectively) Coyotes (jumping after leaving a platformer) Taught tech: Booster jumps (jumping after holding right for more acceleration Slamdashes (dash down then jump) Chain boosts (booster jumps chained to go SUPER FAST) No-dash zones Heroic jumps (wavedash then jump right away) Wallboosting (repeatedly walljumping between walls) Wallbouncing (hitting a wall then walljumping to go faster) Reverse Wavedashes (dash down-left or down-right then jump right or left, respectively)
