In my case, I expected a typical control scheme, but didn't realize that it wouldn't pick up the ball without looking directly at it. Might be worth to specify that too! c: I kept trying to hit "E" while just standing near it and was confused for a bit.
For anyone coming across this later (since I still didn't see any controls listed), it's: standard WASD movement, Space to jump, and E to pick up/drop objects (while it is centered in the screen / you're looking at it). When you're near machines that apply bindings, it will show on-screen what key to press to engage it.