There are two versions of the game and this is quite interesting discovering:

Version 1.0 features:

• Damage boosting, which is kind of interesting. That aspect changes already planned health'n'ammo management (in pre-Zero HP Glitch runs) resulting in complex of time saving.

• You can duplicate weapons and ammo with the same way as in Deus Ex. Hit your drop key rapidly and here you go. Also sometimes game gives you two weapons even if you picked up only one.

• No "Cabal Safehouse" skip, you can't clip through that gate and you have to trigger the cutscene on the roof of hotel.

• Zero HP Glitch doesn't work in this version.

Version 2.1.233 features:

• The main feature of this version is Zero HP Glitch, which ruins the entire game. It allows you be fully invulnerable and invisible to enemies and move fast in places where you have to crouch. To get this, frame where death animation starts must be skipped. Easiest way to skip it - making a frame perfect quick save (game skips couple of frames then). Also you have to receive damage from physical entities: explosion, flare, laser or any other death trigger. It works in any game mode by the way. Glitch was discovered years ago by many people in Blood Community but was never used in runs before me. To make it more clear, that glitch presented in my and @hipp0cat runs (UPD 2021: these runs are in Latest subcategory now).

• You can clip through the gate in "Cabal Safehouse" level and skip hotel section.

• There is no weapon duping.

• There is no damage boosting.

Demo versions:

Demo version consist of two levels: Center for Disease Management and Movin' On Up. Also, demo has two (!!!) versions: 1.0 and 1.0a (Latest). The only difference between them is that v1.0 is slower than v1.0a: for some reason Caleb's speed differs significantly, so "Any% Demo" has subcategories as well as main categories.