SMBX: Take it What Now? - 39.202
This level was really satisfying to run. This is an A2XT level, but it was easier to include it as an IL with the timer instead of being part of the original game. This means that we don't hear the proper sound effects and we play as Mario instead of Demo, but gameplay is unaffected.
I'm really glad that we couldn't pick Toad here because it would have been a lot less fun. Mario has a trick where he can slide up hills to avoid losing speed, making it possible to remove nearly all speed loss from the hills with good play. Sub-39 is probably possible with these strats, but it would probably require nigh frame-perfect play. Saving a second on the hill before the midpoint is probably possible by throwing a Marisa and jumping off of her in midair, but I didn't pull off that trick in this run.