The credits and ending are found after beating the boss; the player falls down and the creators names are listed:
DOWNWELL a game by OJIRO FUMOTO sound design by JOONAS TURNER music & sound design by EIRIK SUHRKE additional art & japanese font by NEMK DEVOLVER DIGITAL FORK PARKER GRAEME STRUTHERS RICK STULTS HARRY MILLER MIKE WILSON NIGEL LOWRIE NICK TODD JOHN BARTKIW JUSTIN BURNAM KERT GARTNER E-STUDIO special thanks KAN KOHEI KIMURA YOICHI OKAMOTO MASUHIRO OHIRA
(You can skip the credits by pressing the "shoot" button. The boy falls for a while, before finally hitting the bottom of the well. There, he sees a cat. He picks it up and uses his gunboots to propel himself back towards the surface.)