I rappelled the first level in leisurely fashion and a passing consideration for the extra gems. The second level refused to pull punches, however, and after five minutes spent failing to acquire one, I switched my focus towards the clock and finishing out the game; this felt like the correct choice after being faced with the length and difficulty of each level's "final trial," which is a grand step up from most other areas. I'd like to imagine a secret fourth level opening in the absent space on the map once I collect all the chaos emeralds, but an hour of playtime with the normal ending will have to do for now.
The game is pretty overtly focused on a single item, with the consequential moods and events that are probably the most abundant in gaming as a whole aside from Nerve beaters. This is a case where music is doing a lot of heavy lifting for the distinction between locations, as well as some other flairs like the map intro, color palette, and well-paced variance.
I've been slowly working my way through Symphony of the Night, seeing as I have no point of reference for the series, despite it attaching its namesake onto the portmanteau-like genre with which I have plenty of experience generally and in Metroid specifically. I'll have to check the earlier methods of saves and checkpoints, since I believe that to be a rather pivotal element to what puts games within the milieu or not.