Making it more like Doom95

Sprite scaling

Go in r_main.c and locate the following lines:

    // psprite scales
    pspritescale = FRACUNIT*viewwidth/SCREENWIDTH;
    pspriteiscale = FRACUNIT*SCREENWIDTH/viewwidth;

Replace the sprite scaling calculation code with:

    pspritescale = FRACUNIT*(viewwidth*1.2)/(SCREENWIDTH);
    pspriteiscale = FRACUNIT*(SCREENWIDTH)/(viewwidth*1.2);

This will make the weapon sprite bigger and ugly, just like Doom95.

Sound pitch

Go in i_sound.c and locate the function I_StartSound.

Replace the line return SFX_PlayPatch(data, sep, pitch, vol, 0, 100); with return SFX_PlayPatch(data, 120, sep, vol, 0, 100);.

Sounds will play at a lower pitch.