Supersonic was an instant hit on release. Extremely difficult, full to the brim with top creators, and with high-energy pacing throughout, it's easy to see why it was so beloved. Its success led to the equally beloved Ultrasonic, and then to the (initially) controversial Hypersonic and Subsonic. It's clear this level has a deep legacy, but how does it hold up?

A 1.9 level full of top creators is almost guaranteed to be well decorated and this is no exception. There's multiple standout sections - Jeyzor's iconic multicoloured wave leads to a really cool ufo section where invisible saws are indicated by pulsing white objects, DaddePro expertly weaves effects into the sole slow part, Evasium's (known here as Tootti) dual has some cool chevron-esque decoration in the background, which adds to the feeling of speed, and Gboy's purple part is one of the highest quality in the level. Sections like these have inspired countless creators ever since. Of course, there's some weaker sections, like Sumsar's, which isn't bad, it's just not interesting, and also Xcy7's, which, while complimented with a pretty unique colour scheme, doesn't try anything particularly of note, and ends up being forgotten compared to the parts after.

Naturally, Supersonic is more remembered for its difficult gameplay. This was one of the hardest levels in the game upon release, and it's got some revolutionary gameplay in it. The quality of this gameplay is very mixed. Many parts, especially in the first half, are a standard (if challenging) affair, and certain parts (like Xcy7's) are somewhat enjoyable, but there's nothing that stands out. It really gets interesting at Evasium's dual, which has a particularly awkward click pattern in the first half, and a very challenging dual ball second half, which feels very inconsistent to play. It's a nasty difficulty spike, and one which often feels unfair. Immediately after this, Gboy adds insult to injury with a phenomenally awful transition - this really does feel like complete chance, and it either spells instant death, or an extremely unconvincing entrance into what is otherwise a pretty standard ship section. Viprin's ball maze requires a mention - it's nothing special here (hardly more interesting than the one in RobTop's Theory of Everything 2), and it's far outclassed by the other three entries in the series, but at least it's interesting. The ending is a little difficulty spike as well, but while hard, it doesn't really come at the cost of enjoyment, and it's a serviceable end to the level.

It would be wrong to write off Supersonic as nostalgia fodder; there's quality to be found here. The reality is though, that it's outclassed by later 1.9 levels in every way. The main thing it does have going for it is its memorability - throughout the years, Supersonic has never come close to being forgotten. It's a popular entry point into insane demons, and while it may not be the absolute best, it's certainly better than Panasonic.