Arrow Keys and ZXC
Mouse isn't really used.
The $7.99 price tag made me delay downloading the game, but I'm glad I eventually did, because it turned out to be a very emotionally satisfying experience. It's basically Banjo Kazooie's Treasure Trove Cove on steroids. It's also extremely easy to pair with JoyToKey, making it cleanly compatible with hundreds of controllers. This extreme level of controller-friendliness causes the game to meet the criteria for appearing in a special collection, on conflexgames.com.