diff --git a/extra/jamshred/game/game.factor b/extra/jamshred/game/game.factor
index 96cdb60443..94905947f7 100644
--- a/extra/jamshred/game/game.factor
+++ b/extra/jamshred/game/game.factor
@@ -5,7 +5,7 @@ IN: jamshred.game
 TUPLE: jamshred tunnel players running ;
 
 : <jamshred> ( -- jamshred )
-    <random-tunnel> "Player 1" <player> 1array f
+    <random-tunnel> "Player 1" <player> 2dup swap play-in-tunnel 1array f
     jamshred construct-boa ;
 
 : jamshred-player ( jamshred -- player )
@@ -14,7 +14,7 @@ TUPLE: jamshred tunnel players running ;
 
 : jamshred-update ( jamshred -- )
     dup jamshred-running [
-        jamshred-player update-player
+        dup jamshred-tunnel swap jamshred-player update-player
     ] [ drop ] if ;
 
 : toggle-running ( jamshred -- )
diff --git a/extra/jamshred/gl/gl.factor b/extra/jamshred/gl/gl.factor
index 0b58f14bed..ef642fcefd 100644
--- a/extra/jamshred/gl/gl.factor
+++ b/extra/jamshred/gl/gl.factor
@@ -6,8 +6,11 @@ IN: jamshred.gl
 : min-vertices 6 ; inline
 : max-vertices 32 ; inline
 
-: n-vertices ( -- n )
-    32 ; inline
+: n-vertices ( -- n ) 32 ; inline
+
+! render enough of the tunnel that it looks continuous
+: n-segments-ahead ( -- n ) 50 ; inline
+: n-segments-behind ( -- n ) 50 ; inline
 
 : draw-segment-vertex ( segment theta -- )
     over segment-color gl-color segment-vertex-and-normal
@@ -25,8 +28,9 @@ IN: jamshred.gl
 : draw-segments ( segments -- )
     1 over length pick subseq swap [ draw-segment ] 2each ;
 
-: draw-tunnel ( tunnel -- )
-    tunnel-segments draw-segments ;
+: draw-tunnel ( player tunnel -- )
+    tuck swap player-nearest-segment segment-number dup n-segments-behind -
+    swap n-segments-ahead + rot sub-tunnel draw-segments ;
 
 : init-graphics ( width height -- )
     GL_DEPTH_TEST glEnable
@@ -57,6 +61,6 @@ IN: jamshred.gl
     oint-up first3 gluLookAt ;
 
 : draw-jamshred ( jamshred width height -- )
-    init-graphics dup jamshred-player player-view
-    jamshred-tunnel draw-tunnel ;
+    init-graphics dup jamshred-player dup player-view
+    swap jamshred-tunnel draw-tunnel ;
 
diff --git a/extra/jamshred/player/player.factor b/extra/jamshred/player/player.factor
index b339e599c4..f79edf8bdf 100644
--- a/extra/jamshred/player/player.factor
+++ b/extra/jamshred/player/player.factor
@@ -1,5 +1,5 @@
-USING: jamshred.game jamshred.oint jamshred.tunnel kernel
-math.constants ;
+USING: colors jamshred.game jamshred.oint jamshred.tunnel kernel
+math.constants sequences ;
 IN: jamshred.player
 
 TUPLE: player name speed last-segment ;
@@ -8,13 +8,18 @@ TUPLE: player name speed last-segment ;
     1 f player construct-boa
     { 0 0 5 } { 0 0 -1 } { 0 1 0 } { -1 0 0 } <oint> over set-delegate ;
 
-: update-player ( player -- )
-    0.1 swap go-forward ;
-
 : turn-player ( player x-radians y-radians -- )
     >r over r> left-pivot up-pivot ;
 
+: play-in-tunnel ( player tunnel -- )
+    tunnel-segments first dup oint-location pick set-oint-location
+    swap set-player-last-segment ;
+
 : player-nearest-segment ( tunnel player -- segment )
     [
         dup player-last-segment nearest-segment
     ] keep dupd set-player-last-segment ;
+
+: update-player ( tunnel player -- )
+    0.1 over go-forward player-nearest-segment white swap set-segment-color ;
+
diff --git a/extra/jamshred/tunnel/tunnel.factor b/extra/jamshred/tunnel/tunnel.factor
index 42f0ee3469..9320ea84d3 100644
--- a/extra/jamshred/tunnel/tunnel.factor
+++ b/extra/jamshred/tunnel/tunnel.factor
@@ -1,8 +1,8 @@
-USING: arrays kernel jamshred.oint math math.functions math.vectors
+USING: arrays kernel jamshred.oint math math.functions math.ranges math.vectors
 math.constants random sequences vectors ;
 IN: jamshred.tunnel
 
-: n-segments ( -- n ) 100 ; inline
+: n-segments ( -- n ) 5000 ; inline
 
 TUPLE: segment number color radius ;
 
@@ -71,18 +71,31 @@ C: <tunnel> tunnel
 : <straight-tunnel> ( -- tunnel )
     n-segments simple-segments <tunnel> ;
 
+: sub-tunnel ( from to tunnel -- segments )
+    #! return segments between from and to, after clamping from and to to
+    #! valid values
+    tunnel-segments [
+        sequence-index-range [ clamp-to-range ] curry 2apply
+    ] keep <slice> ;
+
 : nearer-segment ( segment segment oint -- segment )
     #! return whichever of the two segments is nearer to the oint
     >r 2dup r> tuck distance >r distance r> < -rot ? ;
 
+: (find-nearest-segment) ( nearest next oint -- nearest ? )
+    #! find the nearest of 'next' and 'nearest' to 'oint', and return
+    #! t if the nearest hasn't changed
+    pick >r nearer-segment dup r> = ;
+
 : find-nearest-segment ( oint segments -- segment )
-    tuck first swap [ -rot nearer-segment ] curry reduce ;
+    dup first swap 1 tail-slice rot [ (find-nearest-segment) ] curry
+    find 2drop ;
     
 : nearest-segment-forward ( segments oint start -- segment )
     rot dup length swap <slice> find-nearest-segment ;
 
 : nearest-segment-backward ( segments oint start -- segment )
-    1+ 0 swap rot <slice> <reversed> find-nearest-segment ;
+    swapd 1+ 0 swap rot <slice> <reversed> find-nearest-segment ;
 
 : nearest-segment ( tunnel oint start-segment -- segment )
     #! find the segment nearest to 'oint', and return it.