1. I agree with another comment, adding one for flavor would be great, but it should be skippable if it results in the same thing again (the dryad scene and the special vines scene are notable, and should be forced to view at least once)
2. A cutscene, three chase sequences, then another cutscene does feel a bit short, but making it longer could feel repetitive, so it's probably fine.
3. Vines and Dryad scene were great, though the "Hey, if you do this something's gonna happen" in front of the vines could've been shorter. A simple "I don't trust those vines" followed by "Do I really want to chance this? [YES, NO]" would've worked wonders there. You could even do a "I know what these are gonna do to me" thing for repeats, whether that be to avoid them or to prompt the player again, who's to say.
4. The science scenes were fun, and made for some excellent world-building. The fact that you physically need a dryad seed to do the third science was a bit annoying, especially since the event that gives you them is from losing, AND it explicitly says "Just sell these"
5. N/A (I appreciate all the work of getting a Mac port up and running)
6. I did! It took me a second to see it since it's tucked away a bit, as all debug-y things should be.