diff --git a/js/format-c2m.js b/js/format-c2m.js
index da4dd46..8847238 100644
--- a/js/format-c2m.js
+++ b/js/format-c2m.js
@@ -17,7 +17,10 @@ class CC2Demo {
         this.bytes = new Uint8Array(buf);
 
         // byte 0 is unknown, always 0?
-        this.force_floor_seed = this.bytes[1];
+        // Force floor seed can apparently be anything; my best guess, based on the Desert Oasis
+        // replay, is that it's just incremented and allowed to overflow, so taking it mod 4 gives
+        // the correct starting direction
+        this.initial_force_floor_direction = ['north', 'east', 'south', 'west'][this.bytes[1] % 4];
         this.blob_seed = this.bytes[2];
     }
 
@@ -132,7 +135,7 @@ const TILE_ENCODING = {
     0x43: 'cloner',
     //0x44: Clone machine : Modifier required, see below
     0x45: 'hint',
-    //0x46: 'force_floor_all',
+    0x46: 'force_floor_all',
     // 0x47: 'button_gray',
     0x48: ['swivel_sw', 'swivel_floor'],
     0x49: ['swivel_nw', 'swivel_floor'],
diff --git a/js/main.js b/js/main.js
index 46e5167..f3511f8 100644
--- a/js/main.js
+++ b/js/main.js
@@ -383,6 +383,7 @@ class Player extends PrimaryView {
     play_demo() {
         this.demo_faucet = this.level.stored_level.demo[Symbol.iterator]();
         this.restart_level();
+        this.level.force_floor_direction = this.level.stored_level.demo.initial_force_floor_direction;
         // FIXME should probably start playback on first real input
         this.set_state('playing');
     }