diff --git a/game/main.scm b/game/main.scm
index 0149b59..8501495 100644
--- a/game/main.scm
+++ b/game/main.scm
@@ -31,13 +31,11 @@
 (define (update dt)
   (poll-coop-repl-server repl)
   (set! hero 
-    (hero-with-position 
-     hero
-     (set-vec2-x! 
-      (hero-position hero) 
-      (floor-remainder 
-       (+ (vec2-x (hero-position hero)) 
-          (* 50.0 dt)) 608.0)))))
+    (hero-with-x 
+     hero 
+     (floor-remainder 
+      (+  (hero-x hero) (* 50.0 dt)) 
+      608.0))))
 
 (define (draw _alpha)
   (render-level-draw level)
diff --git a/game/model/hero.scm b/game/model/hero.scm
index 61f8834..b382a92 100644
--- a/game/model/hero.scm
+++ b/game/model/hero.scm
@@ -6,11 +6,11 @@
   #:use-module (chickadee math vector)
   #:use-module (game model level)
   #:export (hero-load
-            hero-x hero-with-x
-            hero-y hero-with-y
             hero-state hero-with-state
             hero-bloat hero-with-bloat
             hero-position hero-with-position
+            hero-x hero-with-x
+            hero-y hero-with-y
             ))
 
 
@@ -29,6 +29,17 @@
   (let ((initial-position (level-find-hero level)))
     (%make-hero initial-position default-state default-bloat)))
 
+(define (hero-x hero)
+  (inexact->exact (floor (vec2-x (hero-position hero)))))
+(define (hero-y hero)
+  (inexact->exact (floor (vec2-y (hero-position hero)))))
+
+(define (hero-with-x hero x)
+  (hero-with-position hero (vec2 x (hero-y hero))))
+
+(define (hero-with-y hero y)
+  (hero-with-position hero (vec2 (hero-x hero) y)))
+
 ;; Tests
 [test-begin "hero model"]
 
@@ -45,6 +56,10 @@
   (test-equal 'go-left (hero-state (hero-with-state hero 'go-left)))
   (test-equal default-state (hero-state hero))
   (test-equal 1.5 (hero-bloat (hero-with-bloat hero 1.5)))
-  (test-equal default-bloat (hero-bloat hero)))
+  (test-equal default-bloat (hero-bloat hero))
+  
+  (test-equal 16 (hero-x (hero-with-position hero (vec2 16.34 20.78))))
+  (test-equal 20 (hero-y (hero-with-position hero (vec2 16.34 20.78))))
+  )
 
 (test-end "hero model")
diff --git a/game/model/level.scm b/game/model/level.scm
index 7a893c3..56b2823 100644
--- a/game/model/level.scm
+++ b/game/model/level.scm
@@ -127,6 +127,7 @@
   (level-tiles (level-parse "--- ignore this line\nWWWWW\nWP GW - must be ignored\nWWWWW\n")) 
   #(wall wall wall wall wall wall hero empty goal wall wall wall wall wall wall))
 
+;; regression test for character parsing
 (test-equal (parse-tile #\W) 'wall)
 (test-equal (parse-tile #\B) 'brick)
 (test-equal (parse-tile #\H) 'ladder)