Fathom is a new platformer from Adam Saltsman, whose indie cred includes Blush, Meat Boy and Wurdle. It starts out in standard side-scrolling fashion as you run from left to right, jumping over obstacles, dodging falling bricks and shooting enemies.
Then you hit the boss fight (pictured) and, well... all I should really say is play it and find out for yourself.
Is there a twist to the standard platforming action? Maybe.
(Hint: If that boss fight seems a little too tough, perhaps you might fare better by sleeping with the fishes.)