diff --git a/acs/swwmcomp.o b/acs/swwmcomp.o
index 53e7d433e..282deba6d 100644
Binary files a/acs/swwmcomp.o and b/acs/swwmcomp.o differ
diff --git a/animdefs.equinoxcompat b/animdefs.equinoxcompat
new file mode 100644
index 000000000..e05809448
--- /dev/null
+++ b/animdefs.equinoxcompat
@@ -0,0 +1,19 @@
+flat optional EQNXSL01
+	pic 1 tics 8
+	pic 2 tics 8
+	pic 3 tics 8
+	pic 4 tics 8
+flat optional EQNXSL09
+	pic 9 tics 8
+	pic 10 tics 8
+	pic 11 tics 8
+	pic 12 tics 8
+flat optional EQNXBLD1
+	pic 1 tics 8
+	pic 2 tics 8
+	pic 3 tics 8
+flat optional EQNXRR05
+	pic 5 tics 8
+	pic 6 tics 8
+	pic 7 tics 8
+	pic 8 tics 8
diff --git a/filter/game-doomchex/TERRAIN.txt b/filter/game-doomchex/TERRAIN.txt
index db485001a..689d82e99 100644
--- a/filter/game-doomchex/TERRAIN.txt
+++ b/filter/game-doomchex/TERRAIN.txt
@@ -775,3 +775,9 @@ floor optional ZFLWATR1 DoomWater
 floor optional ZFLWATR2 DoomWater
 floor optional ZFLWATR3 DoomWater
 floor optional ZFLWATR4 DoomWater
+
+// [MK] Equinox slime
+floor optional EQNXSL01 DoomMud
+floor optional EQNXSL02 DoomMud
+floor optional EQNXSL03 DoomMud
+floor optional EQNXSL04 DoomMud
diff --git a/language.version b/language.version
index b5c52300b..fffeb3861 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\chSWWM \czGZ\c- \cw0.9.11b-pre r260 \cu(Wed 10 Feb 10:40:54 CET 2021)\c-";
-SWWM_SHORTVER="\cw0.9.11b-pre r260 \cu(2021-02-10 10:40:54)\c-";
+SWWM_MODVER="\chSWWM \czGZ\c- \cw0.9.11b-pre r261 \cu(Wed 10 Feb 11:37:30 CET 2021)\c-";
+SWWM_SHORTVER="\cw0.9.11b-pre r261 \cu(2021-02-10 11:37:30)\c-";
diff --git a/swwmcomp.acs b/swwmcomp.acs
index bfae089ff..dc13272fa 100644
--- a/swwmcomp.acs
+++ b/swwmcomp.acs
@@ -40,6 +40,12 @@ SCRIPT "NERVE_EXITOPEN" ( void )
 	Ceiling_RaiseByValue(24,8,80);
 }
 
+SCRIPT "EQUINOX_BRAINCRUSH" ( int tag )
+{
+	SpawnSpotFacing("BossBrain",666);
+	Ceiling_CrushAndRaiseDist(tag,8,8,10);
+}
+
 // this one is for forcing episodes to continue seamlessly
 // will be used eventually
 SCRIPT "EPISODIC_CONTD" ( void )
diff --git a/textures.equinoxcompat b/textures.equinoxcompat
new file mode 100644
index 000000000..ae7ef3c1d
--- /dev/null
+++ b/textures.equinoxcompat
@@ -0,0 +1,60 @@
+flat optional EQNXSL01, 64, 64
+{
+	Patch SLIME01, 0, 0
+}
+flat optional EQNXSL02, 64, 64
+{
+	Patch SLIME02, 0, 0
+}
+flat optional EQNXSL03, 64, 64
+{
+	Patch SLIME03, 0, 0
+}
+flat optional EQNXSL04, 64, 64
+{
+	Patch SLIME04, 0, 0
+}
+flat optional EQNXSL09, 64, 64
+{
+	Patch SLIME09, 0, 0
+}
+flat optional EQNXSL10, 64, 64
+{
+	Patch SLIME10, 0, 0
+}
+flat optional EQNXSL11, 64, 64
+{
+	Patch SLIME11, 0, 0
+}
+flat optional EQNXSL12, 64, 64
+{
+	Patch SLIME12, 0, 0
+}
+flat optional EQNXBLD1, 64, 64
+{
+	Patch BLOOD1, 0, 0
+}
+flat optional EQNXBLD2, 64, 64
+{
+	Patch BLOOD2, 0, 0
+}
+flat optional EQNXBLD3, 64, 64
+{
+	Patch BLOOD3, 0, 0
+}
+flat optional EQNXRR05, 64, 64
+{
+	Patch RROCK05, 0, 0
+}
+flat optional EQNXRR06, 64, 64
+{
+	Patch RROCK06, 0, 0
+}
+flat optional EQNXRR07, 64, 64
+{
+	Patch RROCK07, 0, 0
+}
+flat optional EQNXRR08, 64, 64
+{
+	Patch RROCK08, 0, 0
+}
diff --git a/zscript/swwm_compat.zsc b/zscript/swwm_compat.zsc
index bb65e856b..d7fb30f0a 100644
--- a/zscript/swwm_compat.zsc
+++ b/zscript/swwm_compat.zsc
@@ -5,6 +5,19 @@
 
 Class SWWMLevelCompatibility : LevelPostProcessor
 {
+	private void EquinoxBossBrainHandle( uint lineno, int sectortag )
+	{
+		// don't spawn boss brains until it's time to crush them
+		for ( int i=0; i<GetThingCount(); i++ )
+		{
+			if ( GetThingEdNum(i) != 88 ) continue;
+			SetThingEdNum(i,9001);
+			SetThingID(i,666);
+		}
+		// change the crusher line
+		SetLineSpecial(lineno,ACS_Execute,-Int('EQUINOX_BRAINCRUSH'),0,sectortag);
+	}
+
 	protected void Apply( Name checksum, String mapname )
 	{
 		int numcol = 6;
@@ -55,8 +68,7 @@ Class SWWMLevelCompatibility : LevelPostProcessor
 			int ncellsa = 0, ncellsb = 0;
 			for ( int i=0; i<GetThingCount(); i++ )
 			{
-				int tn = GetThingEdNum(i);
-				if ( tn != 17 ) continue;
+				if ( GetThingEdNum(i) != 17 ) continue;
 				Vector3 pos = GetThingPos(i);
 				if ( pos.y != 480. ) continue;
 				if ( pos.x == -5472. )
@@ -71,6 +83,24 @@ Class SWWMLevelCompatibility : LevelPostProcessor
 				}
 			}
 			break;
+		// Equinox MAP04
+		case 'E66BCCFAD7AC40EFB21E2A19131E1522':
+			EquinoxBossBrainHandle(2406,27);
+			// raise floor by 10 units so its untextured lower lines don't glitch out at eye level
+			OffsetSectorPlane(248,0,10.);
+			break;
+		// Equinox MAP07
+		case 'A0B6B83DC8BD50FC84170572840DE585':
+			EquinoxBossBrainHandle(3423,31);
+			break;
+		// Equinox MAP10
+		case 'F91E3FE225F10EECBE21486E1BB14834':
+			EquinoxBossBrainHandle(2813,29);
+			break;
+		// Equinox MAP13
+		case '3805A661D5C4523AFF7BF86991071043':
+			EquinoxBossBrainHandle(4106,60);
+			break;
 		// Kinsie's Test Map (HERETIC)
 		case '0EADB2F82732A968B8513E4DC6138439':
 			numcol = 7;
@@ -83,5 +113,40 @@ Class SWWMLevelCompatibility : LevelPostProcessor
 				AddThing(4206900+i,(1472+64*i,640,0));
 			break;
 		}
+		switch ( checksum )
+		{
+			// ALL of Equinox
+			case '9705315427A2F951A538B23C39199236':
+			case '54E9953A3C1A88641E00AA353BAF46E9':
+			case 'DD3986E184829DAB73160F4C122155F9':
+			case 'B3E6CAE9983EA1DC4D9544DA26118569':
+			case '3E4DFC55EAE85A7FE02DD21ED33AABCA':
+			case 'ECCB69F1BBF91D8F67D8583EA2546863':
+			case 'E66BCCFAD7AC40EFB21E2A19131E1522':
+			case 'A0B6B83DC8BD50FC84170572840DE585':
+			case '9BA1ACB72D878AFA3CB22B810D6CCD9A':
+			case 'A26749D9B9CD70ECED5C7B6BAB6D859E':
+			case '3805A661D5C4523AFF7BF86991071043':
+			case 'F91E3FE225F10EECBE21486E1BB14834':
+			case '838BA30EB0B003C070414093BFDFA72A':
+				// replace certain animated flats with duplicates
+				// this avoids unintended TERRAIN defs from applying to them
+				level.ReplaceTextures("SLIME01","EQNXSL01",0);
+				level.ReplaceTextures("SLIME02","EQNXSL02",0);
+				level.ReplaceTextures("SLIME03","EQNXSL03",0);
+				level.ReplaceTextures("SLIME04","EQNXSL04",0);
+				level.ReplaceTextures("SLIME09","EQNXSL09",0);
+				level.ReplaceTextures("SLIME10","EQNXSL10",0);
+				level.ReplaceTextures("SLIME11","EQNXSL11",0);
+				level.ReplaceTextures("SLIME12","EQNXSL12",0);
+				level.ReplaceTextures("BLOOD1","EQNXBLD1",0);
+				level.ReplaceTextures("BLOOD2","EQNXBLD2",0);
+				level.ReplaceTextures("BLOOD3","EQNXBLD3",0);
+				level.ReplaceTextures("RROCK05","EQNXRR05",0);
+				level.ReplaceTextures("RROCK06","EQNXRR06",0);
+				level.ReplaceTextures("RROCK07","EQNXRR07",0);
+				level.ReplaceTextures("RROCK08","EQNXRR08",0);
+				break;
+		}
 	}
 }