This game is still going strong, with a final content update, Cold Sweat, having been released on January 23! This video has all S ranks, and Bonus Objectives, along with input display. Timestamps further down will help you find what you are struggling with. Hope this video helps you! If anything changes for levels or objectives I'll note it in a pinned comment.
Thanks to the devs for letting me playtest this content!
Here's a link to my All S Ranks video, which has a short tutorial on how to be faster in this game: https://www.youtube.com/watch?v=tmcZe_bONiM
And a link to my playlist of S rank videos: https://www.youtube.com/playlist?list=PL1M9uCwk_ORkqEEh5ZPBq1mxrg3ElnDWd
00:00 - Intro
00:45 - 1. Limbo S
1:48 - 1. Limbo Melee Kills Only
4:04 - 1. Limbo Don't Pick Up Health Or Armor
5:30 - 2. Deep Breath S & Kill All Enemies
6:28 - 2. Deep Breath Headshot Kills Only
8:14 - 3. Clear Skies S
9:27 - 3. Clear Skies Get Kills With Sniper Rifle
10:54 - 3. Clear Skies Kill All Enemies
12:54 - 4. Rigged S
13:50 - 4. Rigged Don't Get Hit By Snipers
14:46 - 4. Rigged Throwing Knife Kills
15:51 - 5. Steel Crops S
16:49 - 5. Steel Crops Gun Kills Only
17:45 - 5. Steel Crops Explosion Kills
18:50 - 6. Pipe Dream S
20:02 - 6. Pipe Dream Get Kills With Sniper Rifle
21:24 - 6. Pipe Dream Kill No Enemies
22:33 - 7. Butterfly Effect S
23:28 - 7. Butterfly Effect Melee Kills Only
25:00 - 7. Butterfly Effect Kill All With Shotgun
IAYB Playlist: https://www.youtube.com/playlist?list=PL1M9uCwk_ORnJ2AksBKKeYaIxEkVo_83w