In celebration of the beta for the new DOOM running this weekend (#FightLikeHell), DOOM Retro v2.1 is now available. It may be downloaded here, and its release notes are as follows:

• Optimizations have been made to further improve the overall performance and stability of DOOM Retro.
• Support has been added for the SWITCHES lump.
• Fast monsters can now be enabled by using the fastmonsters CCMD. Also, –fastmonsters as well as just –fast can be specified on the command-line.
• Warnings displayed when parsing DeHackEd files and lumps are now only displayed if –devparm is specified on the command-line.
• Automatically loading the last savegame when the player dies can now be disabled by using the autoload CVAR.
• The intensity of the red haze effect when the player has the berserk power-up and their fists selected can now be changed using the r_berserkintensity CVAR. The default is 33%.
• Player sprites may now be translucent if they are replaced in a PWAD by using Translucent = 1 for the relevant frame in DeHackEd files and lumps.
• Thing flags specific to DOOM Retro can now be changed using Retro Bits instead of Bits2 in DeHackEd files and lumps.
• A bug has been fixed whereby the use of unknown music names in MAPINFO lumps would cause a crash.
• The s_musicvolume and s_sfxvolume CVARs are now corrected at startup if invalid.
• The faceback CVAR has been renamed to facebackcolor.
• The extraneous brown pixel in the super shotgun is no longer removed if the weapon is changed in a DeHackEd file or lump.
• Further improvements have been made to the appearance of the rocket launcher's muzzle flash.
• DoomEd numbers are now allowed as the parameter for the give, kill and spawn CCMDs.
• The translucency of the super shotgun's muzzle flash is now disabled when the r_translucency CVAR is off.
• A bug has been fixed whereby monsters would not respawn correctly when playing using the Nightmare! skill level.
• The shadow of the player's corpse is now removed when resurrecting using either the resurrect CCMD or the iddqd cheat.
• The console is now hidden when using the iddqd cheat to resurrect the player.
• The screen now goes to black sooner when starting DOOM Retro.
• DOOM II's cast sequence now works correctly when using SMOOTHED.WAD.
• The console can no longer be opened during a screen wipe.
• The bottoms of things that bob in liquid now animate.
• A bug has been fixed whereby no monsters had lower pitches when the s_randompitch CVAR was enabled.
• The error message displayed when doomretro.wad is invalid has changed.
• bfg is now allowed as a parameter for the spawn and give CCMDs.
• A bug has been fixed whereby the player was unable to switch back to the selfie stick once obtained in InstaDoom.
• The last savegame will no longer be automatically loaded when the player dies of the pistolstart CVAR is enabled.
• Individual monster kill counts used by the playerstats CCMD are now retained in savegames. Please note that this breaks savegame compatibility with previous versions of DOOM Retro.
• The speed of the player can now be changed using the turbo CVAR. Functioning like the command-line parameter of the same name, it can be a value between 10% and 400% and has a default of 100%.
• A bug has been fixed (that is present in Vanilla DOOM) whereby the player would go in reverse when running if their speed was set to a value greater than 255% using the –turbo command-line parameter.
• Monsters can now respawn when playing a skill level other than Nightmare! by using the respawnmonsters CCMD. The –respawn command-line parameter has also been reimplemented, and –respawnmonsters may also be used.
• The value set by Max Health in DeHackEd files and lumps is now only applied to health bonuses.
• 100 extra things (numbered 152 to 251) have been added for use in DeHackEd files and lumps.
• Things with the same (x,y,z) coordinates now bob in sync with each other if they are in liquid.
• The arachnorbs in valiant.wad are now killed when using the kill CCMD.
• Map names changed using a MAPINFO lump are now shown in the output of the maplist CCMD.
• The WINDOWS key can no longer be used at any time when fullscreen. It can only be used when in a window, and the game is paused, or the menu or console is open.
• Wall textures that are both animated and translucent can now be rendered correctly without causing a crash.
• The E key may now be pressed as an alternative to SPACE to use doors, switches, etc. It is bound to the +use2 action.
• When the vid_showfps CVAR is enabled, the frames per second is now displayed correctly while the screen shakes when the player is injured.