The concept is interesting, but I think it could be executed a little better, most of the time I found myself just grabbing the slimes, going to the edge of the platform and releasing them so they die of fall damage, I didn't use the rocket boost even once (and I could not as there was not enough fuel). There should be more obstacles to make the game more challenging, as otherwise it is just throwing slimes off the edges.
I would suggest to make a level where you have to break a wall to continue and make it so that the rocket boost can destroy that wall, that way the player will have an excuse to use the rocket boost. Also scatter some powerups through out the level which replenish the fuel, and to make the game more challenging, make it so the fuel drains faster over time. And maybe make it so that slimes only die if they land on spikes, and not because of fall damage, that way the player will have to think of new ways to get rid of those slimes and it will make the level design easier as the number of ways the slimes can die will reduce.
Overall an interesting entry to the jam! Great job!