Thanks for replying! First I think the initial levels are great, they're a nice level of simplicity to get a feel for what's going on with the game with low stakes. I think more mechanics would be confusing. And for speed up, a fast-forward button or something like that could be even better but I know that kind of thing can also be tricky.
I did also notice the score, early on it seemed pretty closely tied to getting longer times so I figured they tracked mostly the same thing. But if there's much more that goes into it, showing a "best score" tracked with the number and not just stars would be incentive to replay more as well.
Good to know about the path preview! Personally if it were me, I'd turn that on always and not bother making it a toggle in a menu. Maybe if you feel it's distracting you could make it a subtle glow or a trail of footsteps instead of a hard line or something. But I get why you'd want it off by default as a design decision, your game not mine!