Neon Beats

The completion process of Neon Beats is mainly centered around completing each level quickly, without dying, and with all 3 collectible music notes. Many achievements stack. There's a couple other easter egg achievements in this game as well. Do note that a $2 DLC is required to 100% this title.

I've put together videos for all of these achievements, as well as the times necessary to complete each level (not listed in-game). This guide will cover every achievement in the game in video form. Following exactly what I do should hopefully get you 100% in around 5-6 hours.

Full YouTube playlist:
https://www.youtube.com/playlist?list=PL4mzoQnKpJBTnGYKYCdcXkxzhmMWNhlOU

Tutorial
The Tutorial level must be completed with no deaths and all three collectibles in under 2 minutes. This is a relatively easy feat.
Tutorial No Death 100% Speedrun in 0:56.32

Level 1
Level 1 must be completed with no deaths and all three collectibles in under 2 minutes.
Level 1 No Death 100% Speedrun in 1:53.34

Level 2
Level 2 must be completed with no deaths and all three collectibles in under 3 minutes. You'll probably have lots of time to spare, so take it slow if need be.
Level 1 No Death 100% Speedrun in 1:53.34

Level 3
Level 3 must be completed with with no deaths and all three collectibles in under 2 minutes. Once you've done the tutorial and first three levels (base game), you should unlock the Neon Beast achievement.
Level 3 No Death 100% Speedrun in 1:27.55

DLC - Level 4
Level 4 must be completed with no deaths and all three collectibles in under 2 minutes and 10 seconds. This one is pretty lenient.
Level 4 No Death 100% Speedrun in 1:31.51
This level also contains the achievement Day 146 among them, no one suspect a thing... which unlocks by jumping into a corner next to some spikes early on in the level.
"Day 146 among them, no one suspect a thing..." Achievement

DLC - Level 5
Level 5 must be completed with no deaths and all three collectibles in under 2 minutes and 40 seconds. This is the easiest DLC level to speedrun in my opinion.
Level 5 No Death 100% Speedrun in 2:26.69

DLC - Level 6
Level 6 must be completed with no deaths and all three collectibles in under 2 minutes and 45 seconds. This one is also pretty lenient.
Level 6 No Death 100% Speedrun in 2:06.36
This level also contains the achievement They can't reach you! which unlocks by getting on top of a spike corridor in the level with some gravity-switchers.
"They can't reach you" Achievement

DLC - Level 7
Level 7 must be completed with no deaths and all three collectibles in under 2 minutes and 20 seconds. Once again, plenty of time if you know what you're doing.
Level 7 No Death 100% Speedrun in 1:49.53

DLC - Level 8
Level 8 requires two speedruns: no deaths and all three collectibles in under 3 minutes and 30 seconds, and any% in under 2 minutes and 40 seconds.
Level 8 No Death 100% Speedrun in 2:50.01
Level 8 Any% Speedrun in 2:32.66

Congratulations! If you did all 10 speedruns, then you're done with the game.