as a demo, this is great! i do think the controls need to be better refined, the up and down buttons being specials by default is a neat idea however still needing to hold one of them to get extra height from a spring was weird to get used to. im just excited to see whatever the full release might look like!
yes, while you can customize the keybinds, its important to make sure the defaults feel nice to use. customization should be simply an option, not a requirement. even with the keybinds, the issue of them being on the same button is still present as you cannot change them separately. changing the abilities to a different button will also drag the button to boost spring jumps along with it.