Heavy atmosphere and ballooning species.

let's say you have a planet with a dense $Co_2$ atmosphere then plant life could use vacuoles or multicellular sacs filled with a lifting gas. If they are mat forming then the mats would be moving platforms.

If there are free floating small critters than larger filter-feeding things with floatation bladders could chase them about.

Heavy atmosphere and biological balloons would solve most of your requirements.

High jumping would be achieved through bouyancy

Heavy atmosphere and ballooning species.

let's say you have a planet with a dense $Co_2$ atmosphere then plant life could use vacuoles or multicellular sacs filled with a lifting gas. If they are mat forming then the mats would be moving platforms.

If there are free floating small critters than larger filter-feeding things with flotation bladders could chase them about.

Heavy atmosphere and biological balloons would solve most of your requirements.

High jumping would be achieved through buoyancy.