Dev here: I agree, it's actually a line item in my todo list. That being said, many of them can be made to be very quick via command line arguments without losing the spirit of the effect.
I have not implemented gravity, haha. I have actually worked on a custom terminal game engine in the past and realized with TTE I am very small amount of scope creep away from landing in that territory again. I promised myself I will not implement physics or collision. Keeping it simple. That being said, as with the example pour syntax above, all of the effects have a ton of config options to allow for most obvious variations.
