diff --git a/apps/plugins/boomshine.lua b/apps/plugins/boomshine.lua
index 2eb43de..cc3f5a6 100644
--- a/apps/plugins/boomshine.lua
+++ b/apps/plugins/boomshine.lua
@@ -63,7 +63,7 @@ function Ball:new(o)
                 color = random_color(),
                 up_speed = Ball:generateSpeed(),
                 right_speed = Ball:generateSpeed(),
-                explosion_size = math.random(2*self.size, 4*self.size),
+                explosion_size = math.random(2*self.size, 4*self.size) * 4/3,
                 life_duration = math.random(rb.HZ, rb.HZ*5)
             }
     end
@@ -82,6 +82,26 @@ function Ball:generateSpeed()
     return speed
 end

+function drawCircle(x0, y0, radius)
+  x = radius
+  y = 0
+  radiusError = 1 - x
+  step = 0
+
+  while x >= y do
+    y = y + 1
+    if radiusError < 0 then
+      radiusError = radiusError + 2 * y + 1
+    else
+      rb.lcd_fillrect(x0 - x, y0 - y, 1, 2 * y)
+      rb.lcd_fillrect(x0 + x, y0 - y, 1, 2 * y)
+      rb.lcd_fillrect(x0 - y, y0 - x, 2 * y, 2 * x)
+      x = x - 1
+      radiusError = radiusError + (y - x) + 1
+    end
+  end
+end
+
 function Ball:draw()
     --[[
          I know these aren't circles, but as there's no current circle
@@ -89,7 +109,13 @@ function Ball:draw()
          circles from within Lua is far too slow).
     ]]--
     set_foreground(self.color)
-    rb.lcd_fillrect(self.x, self.y, self.size, self.size)
+
+    xm = math.floor(self.x + self.size / 2)
+    ym = math.floor(self.y + self.size / 2)
+
+    drawCircle(xm, ym, math.ceil(self.size / 2))
+
+    --[[ rb.lcd_fillrect(self.x, self.y, self.size, self.size) ]]--
 end

 function Ball:step()
@@ -119,8 +145,12 @@ function Ball:step()
 end

 function Ball:checkHit(other)
-    if (other.x + other.size >= self.x) and (self.x + self.size >= other.x) and
-       (other.y + other.size >= self.y) and (self.y + self.size >= other.y) the
+    dx = (other.x + other.size / 2) - (self.x + self.size / 2)
+    dy = (other.y + other.size / 2) - (self.y + self.size / 2)
+    ds = (other.size / 2 + self.size / 2)
+    if dx*dx + dy*dy   -- Distance between centers, squared
+       <=
+       ds * ds then    -- Sizes, squared
         assert(not self.exploded)
         self.exploded = true
         self.death_time = rb.current_tick() + self.life_duration
@@ -212,7 +242,7 @@ function random_color()
 end

 function start_round(level, goal, nrBalls, total)
-    local player_added, score, exit, nrExpandedBalls = false, 0, false, 0
+    local player_added, score, exit, nrExpendedBalls = false, 0, false, 0
     local balls, explodedBalls = {}, {}
     local cursor = Cursor:new()

@@ -257,7 +287,7 @@ function start_round(level, goal, nrBalls, total)
             for _, explodedBall in ipairs(explodedBalls) do
                 if ball:checkHit(explodedBall) then
                     score = score + 100*level
-                    nrExpandedBalls = nrExpandedBalls + 1
+                    nrExpendedBalls = nrExpendedBalls + 1
                     table.insert(explodedBalls, ball)
                     table.remove(balls, i)
                     break
@@ -280,7 +310,7 @@ function start_round(level, goal, nrBalls, total)
         rb.lcd_clear_display()

         set_foreground(DEFAULT_FOREGROUND_COLOR)
-        draw_positioned_string(0, 0, string.format("%d balls expanded", nrExpan
+        draw_positioned_string(0, 0, string.format("%d balls expended", nrExpen
         draw_positioned_string(0, 1, string.format("Level %d", level))
         draw_positioned_string(1, 1, string.format("%d level points", score))
         draw_positioned_string(1, 0, string.format("%d total points", total+sco
@@ -309,7 +339,7 @@ function start_round(level, goal, nrBalls, total)
         end
     end

-    return exit, score, nrExpandedBalls
+    return exit, score, nrExpendedBalls
 end

 -- Helper function to display a message
@@ -353,17 +383,19 @@ if HAS_TOUCHSCREEN then
 end
 rb.backlight_force_on()

+math.randomseed(os.time())
+
 local idx, highscore = 1, 0
 while levels[idx] ~= nil do
     local goal, nrBalls = levels[idx][1], levels[idx][2]

     display_message(rb.HZ*2, "Level %d: get %d out of %d balls", idx, goal, nrB

-    local exit, score, nrExpandedBalls = start_round(idx, goal, nrBalls, highsc
+    local exit, score, nrExpendedBalls = start_round(idx, goal, nrBalls, highsc
     if exit then
         break -- Exiting..
     else
-        if nrExpandedBalls >= goal then
+        if nrExpendedBalls >= goal then
             display_message(rb.HZ*2, "You won!")
             idx = idx + 1
             highscore = highscore + score