At its core, "Omega Scarlet" is a 2.0 update of the level "Alpha Scarlet". It's not necessarily an entire remake or revamp of the level, especially as it retains the same core skeleton as its predecessor. However, this time, it features an updated moving background, text to go along with the lyrics as well as very few, minute changes to the gameplay of the original "Alpha Scarlet". Unfortunately, I think it's definitely much messier than the original "Alpha Scarlet". In the original "Alpha Scarlet", the flashing blocks and colors were already enough for the level to mesh well with the music however in "Omega Scarlet", the newly-added background is just distracting and makes the level feel considerably cluttered. I think the addition of lyrics during the pre-drop ship also makes the level feel much more cluttered than its predecessor, especially because they cause you to divert your eyes away from the gameplay (which is already kind of a problem in a level that's as flashy and noisy as the original "Alpha Scarlet"). It's essentially a carbon copy of the original save for its few changes so it can't help but feel like a rushed asset flip.

Regardless, I do respect the fact that Thomaisho decided to upload "Omega Cosmos" separately from "Alpha Cosmos" as it easily could have passed as a 2.0 'improvement' to its predecessor. Lots of older levels certainly fall victim to being updated later on and in the process of doing so, can get worse (for example, the infamous levels "Gravity Cycles" and "Theory of Relativity" were updated in 2.1 and 2.0 respectively and barely anybody actually likes these levels). Ironically enough, Thomaisho's own level "Magnolia" was also updated in 2.1 (but I can't comment on its quality as I haven't beaten it).