Just reached Cortex Castle.
I abhor square turns AND THIS IS EVERYTHING. :(
Haha.
As someone who the only thing, outside of Oxide ghosts, I could never do on the original CTR was unlock the Tropy ghost for that track, it's definitely doable.
I spent a couple of days on it on this version, and not only did I unlock the Tropy ghost after like however many years, I ended up beating the Oxide ghost by a pretty decent amount.
The biggest things to note are:
Air braking is key for taking corners, especially near the start where you can choose to go either left or right. If you air brake as you jump, even if you lose sacred fire, you'll be able to basically hug the corner as you turn, and you'll get a boost as you land. Air brake with square and diagonally down in the direction you want to turn, after you hop off something.
The shortcut is nightmarish, and you don't really need to take it outside of time trials/online against decent players.
At the super turbo ramp at the end of the track, just after the shortcut, you want to try and preserve that blue fire for as long as possible. Generally, the spider that is lowered when you land is going to be the one you go through, so keep that in mind. But yeah, if you drift past the spider, and around the corner both before and after the starting line, you can maintain blue fire. That'll give you a big lead.