This reminds me of a game that I've seen (but never played) called "Doodle Jump", is it a remake/homage?

Suggested quality-of-life improvement, the menus all have to be navigated with mouse but the gameplay is with keyboard. It's very tedious to go back and forth. Just make the menus navigable with keyboard also.

As for the gameplay, the complete lack of inertia makes it very difficult. Horizontal movement seems to be the same both on ground and in air, and is way too fast. There's not acceleration or deceleration, everything just happens instantaneously. No coyote time or any other polish on platforming mechanics. Deaths always seem unfair.