Ah. Until I just made another course, I completely forgot to say. I actually found this one by checking you out as another person that beat Birb's course (before you posted it here), and really enjoyed it!
I'd say the star is kinda pointless. I tried to follow that tip, but couldn't really get through there. Or maybe I just didn't try as much as I do on some expert sections at times, but I don't remember it being enough to get you all the way through the spikes with just it. Boot & Flower did the trick, but dunno if it was intended that you can get as many power ups as you want if you choose the boot first...
This level... took a few hours for sure, but definitely spanned a couple weeks at least thinking of how I could make it work, making a bit at a time... Based on a boss from Blaster Master Zero 2... coincidentally also on a planet our heroes travel to.
YH6 9S6 BGF
One thing was I focused on appearance more than finding a way to actually make the giant boss move, even a little, but I know it still doesn't look that good. Another is that I wish I could use checkpoints, but I heard that you can't with clear conditions (didn't try it, though). I had to make it something to do with beating the little guys within the big one, since that is the whole point of the boss. This is where I think even with the compromises I made to try to make it easier, it might be ridiculously hard, given the way I thought of making the fight accurate.
Another section though, I compromised again with the donut blocks, but I realized they actually lead pretty accurately to where you might use the hover ability, and they're pretty much necessary if I wanted an accurate placement of everything else in that section.
I was thinking of seeing if I can upgrade my Alice stage, given the more options we have (especially the fact that I can make water on only a small part of the stage, I can more accurately add the scene with water). I'm most sad that the costumes are gone because I can't use the Pikmin to depict the shrinking, and there is no Tiny Mushroom! I wonder if there's something that can be done for that... if I really wanted to and thought hard, it might take just a lot of space and look a lot less elegant.