diff --git a/main.lua b/main.lua
index 77950b8..8e3ffa5 100644
--- a/main.lua
+++ b/main.lua
@@ -65,12 +65,18 @@ function make_main_scene_toolbelt()
         false,
         {
             texture = TEXTURES.NEW_GAME_HEX,
-            action = function() game_init() end
+            action = function()
+                win.scene:remove"menu"
+                game_init()
+            end
         },
         false,
         {
             texture = TEXTURES.LOAD_GAME_HEX,
-            action = function() game_init(am.load_state("save", "json")) end
+            action = function()
+                win.scene:remove"menu"
+                game_init(am.load_state("save", "json"))
+            end
         },
         false,
         false,
@@ -191,9 +197,11 @@ function main_scene(do_backdrop)
 
     group:action(main_action)
 
-    return group
+    return group:tag"menu"
 end
 
-win.scene = main_scene(true)
+win.scene = am.group(
+    main_scene(true)
+)
 noglobals()
 
diff --git a/src/game.lua b/src/game.lua
index 693a254..cce1442 100644
--- a/src/game.lua
+++ b/src/game.lua
@@ -23,7 +23,7 @@ local TRDTS = {
 }
 
 local function get_initial_game_state(seed)
-    local STARTING_MONEY = 100000
+    local STARTING_MONEY = 200
     -- 2014
     local map, world = random_map()
 
@@ -45,7 +45,8 @@ local function get_initial_game_state(seed)
         time_until_next_wave = 0,
         time_until_next_break = 0,
         spawning = false,
-        spawn_chance = 55,
+        spawn_chance = 0.01,
+        last_mob_spawn_time = 0,
 
         selected_tower_type = false,
         selected_toolbelt_button = false,
@@ -117,7 +118,7 @@ end
 local function game_pause()
     win.scene("game").paused = true
 
-    win.scene:append(main_scene(false):tag"pause_menu")
+    win.scene:append(main_scene(false))
 end
 
 local function game_deserialize(json_string)
@@ -213,8 +214,6 @@ local function game_action(scene)
     state.time = state.time + am.delta_time
     state.score = state.score + am.delta_time
 
-    state.spawn_chance = math.clamp(state.spawn_chance - math.floor(state.time / 100), 1, 25)
-
     if state.spawning then
         state.time_until_next_break = state.time_until_next_break - am.delta_time
 
@@ -231,6 +230,9 @@ local function game_action(scene)
         if state.time_until_next_wave <= 0 then
             state.time_until_next_wave = 0
 
+            -- calculate spawn chance for next wave
+            state.spawn_chance = (state.current_wave + 1)/200
+
             state.spawning = true
             state.time_until_next_break = get_wave_time(state.current_wave)
         end
diff --git a/src/mob.lua b/src/mob.lua
index 3aff201..60b859e 100644
--- a/src/mob.lua
+++ b/src/mob.lua
@@ -40,8 +40,8 @@ local function grow_mob_speed(mob_type, spec_speed, time)
     -- if it does, a small amount with a horizontal asymptote
     return spec_speed --* math.abs(math.log(time / 100))
 end
-local function grow_mob_bounty(mob_type, spec_speed, time)
-    return spec_speed * (time / 100 + 1)
+local function grow_mob_bounty(mob_type, spec_bounty, time)
+    return spec_bounty * (time / 100 + 1)
 end
 
 function mobs_on_hex(hex)
@@ -313,9 +313,25 @@ function mob_deserialize(json_string)
     return mob
 end
 
-function do_mob_spawning(spawn_chance)
+local function can_spawn_mob()
+    local MAX_SPAWN_RATE = 0.1
+    if not state.spawning or (state.time - state.last_mob_spawn_time) < MAX_SPAWN_RATE then
+        return false
+    end
+
+    if math.random() <= state.spawn_chance then
+        --log('yes %f', state.spawn_chance)
+        state.last_mob_spawn_time = state.time
+        return true
+    else
+        --log('no %f', state.spawn_chance)
+        return false
+    end
+end
+
+function do_mob_spawning()
     --if win:key_pressed"space" then
-    if state.spawning and math.random(spawn_chance) == 1 then
+    if can_spawn_mob() then
     --if #state.mobs < 1 then
         make_and_register_mob(MOB_TYPE.BEEPER)
     end