ClojureScript + core.async + Om + animation-cljs = WIN!

no-bugs.cljs

(defn no-bugs [{:keys [] :as data} owner {:keys []}]
  (reify
    om/IInitState
    (init-state [_]
      {:comm-ch  (chan)
       :obstacle {:x 50 :width 50 :height 50}
       :animated {:x 10}})
    om/IDidMount
    (did-mount [_]
      (let [{:keys [comm-ch]} (om/get-state owner)
            anim (a/init-animated-value owner [:animated :x])
            _ (util/add-document-event-listener
                :keydown
                (fn [e]
                  (let [kc (.-keyCode e)
                        move
                        (condp = kc
                          37 :left
                          39 :right
                          :no-move)]
                    (put! comm-ch {:event move}))))]
        ;COMPONENT EVENT LOOP
        (go (loop []
              (let [{:keys [event data] :as e} (<! comm-ch)
                    x (om/get-state owner [:animated :x])
                    obstacle (om/get-state owner :obstacle)]
                (condp = event
                  :left
                  (do
                    (a/animated-value-fn! anim dec 0 a/linear))
                  :right
                  (do
                    (if (< x (- (:x obstacle) 10))
                      (a/animated-value-fn! anim inc 0 a/linear)))
                  ;no match
                  (println "Unrecognized event::" e)))
              (recur)))))
    om/IRenderState
    (render-state [_ {{:keys [x]} :animated obstacle :obstacle}]
      (let []
        (html
          [:div {:style {:width           "300px"
                         :position        "relative"
                         :height          "300px"
                         :backgroundColor "silver"}}
           [:div {:style {:height          "40px"
                          :width           "300px"
                          :backgroundColor "green"}}]
           [:div {:style {:height          (str (:height obstacle) "px")
                          :position        "absolute"
                          :left            (str (:x obstacle) "px")
                          :width           (str (:height obstacle) "px")
                          :backgroundColor "black"}}]
           [:div {:style {:height          "30px"
                          :position        "absolute"
                          :left            (str x "px")
                          :width           "10px"
                          :backgroundColor "red"}}]])))))