Apparently I haven't given any of the much-wanted feedback on this, so here goes nothing....
Firstly, the I have a hard time remembering the filename when adding the wad in the first place.
Grassy Ridge Zone 1:
Mmm, great flow. And while it was a bit flat in some places, it wasn't a rather large issue. However, if you'd turn your attention to the waterfalls in the open area, there's a bit of work to be done. Starting off, the waterfalls themselves are opaque. While this wouldn't be so bad normally, there just so happens to be platforms in one of them, and I can't tell which. And once I do find the right one, landing a jump onto a platform inside the waterfall is near impossible. After that, there's no way to position your camera in such a way that you have a good idea of what you're doing. Even worse, downward current lags me. Badly. Additionally, I'll Begin's second screenshot show cases some horrendous glitch I care not to describe. So, yeah, transparent water without current plzthnx.
Also, getting out of the river was pain-filled. It took me a while to figure out I could jump back out of the water onto the bank, which ment I had to go downstream, find a spring, and completely lose my sense of direction.
Pine Canyon Zone 1:
Meh, I really liked the old beggining better. Still, the new beginning has more jumps, something I can say it has on the old version. Also, the fourth ring on the last bridge before you exit the cavern was stuck, being 32 units off the ground, not the bridge.
Grand Airship Zone 1:
Too short for any significant problems to arise. However, it didn't feel enough like an airship. If you could put some windows in like the one in Act 3, that should help lotz.
And Grand Airship Zone 3 was an inventive boss level that was decorative and challenging. Not really much to say here.