Unfortunately, there is no key config. You can adjust the volume.
The window size is fixed at 960 x 540.
Use the left and right keys to move horizontally, the up key to jump, and the down key to pass through scaffolding downwards.
Basically, it's a simple game where you jump over holes and obstacles from left to right, collect items and move to the right end, and on certain stages you fall down and move on to the next stage.
The ending will change slightly depending on the number of items you collect, but the upper limit is low, so you don't need to get them all.
Snails are cute, but they often carry parasites and bacteria, so it's best not to touch them with bare hands.
If you do touch it, wash your hands thoroughly with soap and avoid touching near your eyes and mouth.