diff --git a/language.version b/language.version
index 77ea7f84e..b77f0f2e4 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r711 \cu(Wed 28 Dec 11:45:45 CET 2022)\c-";
-SWWM_SHORTVER="\cw1.3pre r711 \cu(2022-12-28 11:45:45)\c-";
+SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r712 \cu(Wed 28 Dec 21:31:00 CET 2022)\c-";
+SWWM_SHORTVER="\cw1.3pre r712 \cu(2022-12-28 21:31:00)\c-";
diff --git a/zscript/player/swwm_player_move.zsc b/zscript/player/swwm_player_move.zsc
index c2da6a7d7..cbe3a005a 100644
--- a/zscript/player/swwm_player_move.zsc
+++ b/zscript/player/swwm_player_move.zsc
@@ -62,9 +62,8 @@ extend Class Demolitionist
 		}
 		// apply bobbing (formula adapted from Unreal)
 		oldbobtime = bobtime;
-		double vel2d = vel.xy.length();
-		if ( vel2d < .25 ) bobtime += .2/GameTicRate;
-		else bobtime += (.5+.8*min(vel2d/10.,3.))/GameTicRate;
+		double vel2d = vel.xy dot vel.xy;
+		bobtime += (1.25+.25*min(vel2d/100.,3.))/GameTicRate;
 		Vector2 bob = (sin(bobtime*180.),sin(bobtime*360.))*player.bob*.25;
 		if ( player.morphtics )
 			bob = (0.,0.);
@@ -262,8 +261,8 @@ extend Class Demolitionist
 			else if ( player.onground && ShouldDecelerate(floorsector) )
 			{
 				// quickly decelerate if we're not holding movement keys
-				// (account for slippery floors, and assume approx .9 friction as "midpoint" for 85% reduction)
-				double fact = clamp(floorsector.GetFriction(0)*.95,.5,1.);
+				// (account for slippery floors, and assume approx .9 friction as "midpoint" for 70% reduction)
+				double fact = clamp(floorsector.GetFriction(0)*.8,.5,1.);
 				vel *= fact;
 				player.vel *= fact;
 			}