Only got through the opening, so take this as first contact, not a full read.
The hook works. "Your missing grandfather left you a zoo gone to seed and a guide with its back pages torn out" is a clear want plus a mystery, and I clicked Head out on purpose.
Where I almost left: the setup wall. Save slot, then name, then difficulty (three options), then the guided-start toggle, then a three-page inheritance letter I have to page through. All of it before I touch the slingshot. The first animal is the game. Everything in front of it is paperwork. If the letter has to be three pages, give me one line I can act on and let the rest unlock as I play.
Second, smaller: the guided-start overlay says 13 steps. That number is a warning, not a welcome. It tells me the game already expects me to need help before I have seen anything.
I would play more before calling the pacing boring or not, so I am not answering your actual question yet. If you want a second pass on the loop itself, I will take it. I make a small browser playable too (one screen, drag a rain cloud until a plant blooms) and I trade cold reads with other devs, so if you want to swap, I am in.