Kersploosh! came out in Japan as a 3DS launch title called Hyu~stone, and was promptly ignored, then forgotten. I'm just going to guess the writing wasn't as clever in Japan as it is here. Here, when you pick the projectile you plan to throw down a well – oh yeah, the game is about rocks, rubber balls, watermelons, etc. falling down wells – there's a short dialogue motivating why the object is going down a well. For example, the rubber ball has apparently been the curse of an unseen character's life, having cost him his job, marriage, etc. And the watermelon just needs to be cooled off.
The whole setup is that the two people in each scene are imagining what the inside of the well looks like as they're chucking stuff down it, resulting in wells that can diverge from reality with spinning traps, giant donuts, floating cookies, water hazards, and more getting between your stone and the bottom of the well. This is mentioned in dialogue, and reinforced with a loading screen that informs you the game is "imagining well interior."
It's not that the game is bad. There's a lot of excitement and skill involved with guiding your projectile down the well, trying to get it through the middle of big frosted donuts, granting a speed boost, and trying to avoid everything else to keep your object from losing all its HP and breaking. It is, of course, designed to be a 3D showcase, as it's a launch 3DS game – with fake, flat wooden donuts tricking you into landing on them, unless you see the lack of depth.
Kersploosh is just, well, not that deep in terms of gameplay. You use the Circle Pad to guide a rock down a well. There are ten wells you unlock, and ten different projectiles, each with a different level of HP and different movement properties. You could unlock everything in one particularly motivated sitting if you wanted to.
It's still fun to replay all the different wells with the different items, and it's really satisfying to get better at navigating all the crazy stuff, in order to improve your time in each. But the real attraction for me is the writing. It's sort of like playing a game for the story, except there's not really a story.
Kersploosh! is available in the 3DS eShop for $2.99.