Hey, great work on your first game! The concept is really cool and I think it's a very creative solution, but as astroindie has mentioned, it's currently really hard to gauge your jumps. Having a marker or any sort of more analogue feedback would definitely help a lot alongside the charging effect on the character. Adding feedbacks helps a lot when trying to teach the player about the mechanics and also as a small visual/audio reward for simply interacting with your systems.
It really gets easier over time, but it's always a good opportunity to challenge yourself as well. Keep on going, looking forward to your next project!