WARNING!
This website contains major spoilers for the game. I really, REALLY recommend you first play the game and try to reach Door 100 on your own before coming here. The game itself wants you to learn from your mistakes and figure things out yourself. Again please try to play this yourself. I highly recommend that you only look through this site if you are seriously stuck and also if you are a complete noob in general to videogames then I encourage you to go over the site briefly.
You stumble into a hotel one late night and cannot leave it. For unknown reasons, you cannot leave. The only things that await you are multiple elevators. You take the elevator because you have no choice and ascend to Floor 1. This is a game all about survival and if you are new to it, here are all the things you need to beat Doors, Floor 1.
*Screenshot taken from Roblox: Doors
*Screenshots taken from Roblox Profiles.
Lightning_Splash
RediblesQW
Ghostly_Wowzers
jasper_creations
Here is a video to watch if you are lost! I only recommend this if you have gone through everything on the site, so come back later. If you want to see and visualize everything that you have learned, then here is a video I have made going over the information I gave on the site. There might be a few issues with audio and lighting lol, I only noticed after I reached Door 90 but going over the video most important concepts are covered well. Have fun watching.