[WEB][Unknown] Game where you play as shapes

Platform: Web

Genre: Puzzle Platformer?

Estimated year of release: Unknown

Art style: Greyscale solid colors; player is white, background is gray, solid objects are black
very geometric

Notable characters: Circle, Square, Triangle

Notable game mechanics: Each shape had a unique ability, you could switch between them
you started with just the circle, then unlocked the square, then the triangle

i remember the triangle could stretch to be taller or wider