I think providing control instructions would've made gameplay more enjoyable. Moreover, I had to get super close to the targets for the ball to even hit which was annoying since most FPS provide you with some range. I also think if you animated the ball hitting the target better it would've made it more satisfying.
The thing that confuses me with this entry though is how it ties in the to 'adventure' aspect of the Jam. However, I believe this could've easily been solved if you gave some sort of story or lore through text the way HALO or COD even does.