Playing the game

• Supports loading dehacked files at the command line, or in WADs (BOOM, MBF)
• Supports PWADs containing sprites and flats (BOOM)
• Save games and demos completely store game parameters (BOOM, MBF)
• Savegames store list of loaded WAD files, warning if wrong files loaded (BOOM, MBF)

Game engine

• Player bobbing improved, optional (BOOM, MBF)
• Friction effects (BOOM), affecting players and monsters (MBF)
• Wind, current, conveyor effects (BOOM)
• Far more flexible scrolling wall/floor types (BOOM)
• Always run (BOOM)
• Weapon change logic overhauled and improved (BOOM)
• Support for friendly monsters, helper dogs (MBF)
• Monster target finding code improved (MBF)
• AI improvements (MBF)
• Bouncy and touchy things (MBF)
• New code pointers (MBF)
• Per-level and animated skies (MBF)
• Generalised line types system gives complete flexibility (BOOM)
• Elevators (BOOM)
• Translucent sprites, walls (BOOM)
• Independent floor and ceiling lighting (BOOM)
• Silent teleports (BOOM)
• Deep water, true underwater areas (BOOM)
• Icon of Sin telefragging made more consistent (MBF)
• Fix large numbers of game bugs (BOOM, MBF, LxDoom)
• Support arbitrary texture heights (BOOM)

Screen

• High resolution support (PrBoom)
• Optional message console, multiple message lines (BOOM)
• Status bar shows health/armour/ammo in colours (BOOM)
• Heads up display, showing ammo, health, keys overlayed on view (BOOM)
• OpenGL renderer which renders as original to software Doom as possible while greatly improving the visual quality (PrBoom)

Multiplayer

• Spy mode improved (BOOM)
• Support for loadgame in a net game (LxDoom)
• Client server style network games (LxDoom)

Automap

• No limit on marks (BOOM)
• Rotation and overlay modes (DOSDoom, LxDoom)
• Map shows coordinates (BOOM), optionally follow pointer (MBF)
• Teleport lines, key doors marked specially (BOOM)
• Keys, secrets visible on map with cheat codes (BOOM)
• Colours fully configurable from menus (BOOM)

Intermission screens

• Par times hidden when not relevant (BOOM)
• Total episode time shown (LxDoom)

Menus

• F1 help screen shows current key setup (BOOM)
• Key bindings, monster behaviour, and compatibility settings all set in menus (BOOM, MBF)

Compatibility

• Game is capable of behaving like any of: original Doom v1.9, Boom v2.02, MBF (BOOM, MBF, LxDoom)
• Plays most original Doom v1.9 demos (more than Boom or MBF)
• Plays most Boom v2.02 demos (apart from levels with friction effects everything should work)
• Plays some DosDoom, earlier Doom, earlier Boom, and LxDoom demos
• Plays all MBF demos
• Auto-correction of common bugs in old levels (MBF), with warnings (LxDoom)
• Fine control of options controlling compatibility and new features (MBF)

Controls

• Greater control of key bindings from in game menus (BOOM)
• More accurate mouse sensitivity control (BOOM, LxDoom)

Misc

• Screenshot code improved, supports BMPs (BOOM)
• Support for ENDOOM and ENDBOOM (BOOM, LxDoom)
• -timedemo and -fastdemo options (BOOM)
• Real time frame rate, segs, visplanes, sprites display (LxDoom)
• Various extra cheat codes (BOOM, LxDoom)

Internals

• Greatly improved internal memory management (BOOM, LxDoom)
• Startup time greatly shortened by lazy generation of some lookups (DOSDoom, LxDoom)
• Removed internal limits (BOOM)

Annie features:

Level design

• Deep water
• Animated skies
• Translucent sprites, walls
• Independent floor and ceiling lighting
• Friction effects
• Wind, current, conveyor effects

Multiplayer

• Full Coop support
• Full Deathmatch support

Other

• New sounds
• New music
• New textures
• New graphics
• Support for friendly monsters, helper dogs
• Modified Spider Mastermind