Some hesitations for the last shell in chapter 1 and in chapter 3.

Lost time on the first shell in Chapter 7. Ideally, you want to get a walljump or land directly in the water to avoid having to dive back in.

I believe it's possible to grab the first shell in Chapter 6 by jumping out of the water instead of climbing on the broken bridge, but I haven't tested it yet

Shell timestamps in the video : 2:14 - 3:05 - 5:43 - 8:48 - 9:37 - 13:02 - 14 : 27 - 16:55 - 19:04 - 23:05 - 25:17 - 25:44 - 34:07 - 35:03 - 37:15 - 42:55 - 45:45 - 46:18 - 48:51