diff --git a/scripts/cels.lua b/scripts/cels.lua
new file mode 100644
index 000000000..dd91813a0
--- /dev/null
+++ b/scripts/cels.lua
@@ -0,0 +1,37 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+  for i = 1,3 do s:newFrame() end
+  assert(#s.frames == 4)
+
+  -- Layer a and b
+  local a = s.layers[1]
+  local b = s:newLayer()
+
+  local ca = { s.cels[1],
+               s.cels[2],
+               s.cels[3] }
+
+  local cb = { s:newCel(b, 1),
+               s:newCel(b, 2, Image(8, 8), 4, 4),
+               s:newCel(b, 3, Image(32, 10), 16, 10) }
+
+  assert(cb[1].bounds == Rectangle(0, 0, 32, 32))
+  assert(cb[2].bounds == Rectangle(4, 4, 8, 8))
+  assert(cb[3].bounds == Rectangle(16, 10, 32, 10))
+
+  -- Check how layer cels are updated when we delete a cel in the middle
+
+  assert(cb[1] == b.cels[1])
+  assert(cb[2] == b.cels[2])
+  assert(cb[3] == b.cels[3])
+
+  s:deleteCel(cb[2])
+
+  assert(cb[1] == b.cels[1])
+  assert(cb[3] == b.cels[2])
+end
diff --git a/scripts/frames.lua b/scripts/frames.lua
new file mode 100644
index 000000000..62319fac3
--- /dev/null
+++ b/scripts/frames.lua
@@ -0,0 +1,25 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local a = Sprite(32, 32)
+  assert(#a.frames == 1)
+  assert(a.frames[1].frameNumber == 1)
+  assert(a.frames[1].duration == 0.1)
+
+  local fr = a:newFrame()
+  assert(#a.frames == 2)
+  assert(a.frames[1].frameNumber == 1)
+  assert(a.frames[2].frameNumber == 2)
+  assert(a.frames[1].duration == 0.1)
+  assert(a.frames[2].duration == 0.1)
+
+  fr.duration = 0.2
+  assert(a.frames[1].duration == 0.1)
+  assert(a.frames[2].duration == 0.2)
+
+  a:deleteFrame(1)
+  assert(a.frames[1].duration == 0.2)
+end
diff --git a/scripts/layer.lua b/scripts/layer.lua
new file mode 100644
index 000000000..c0494dc54
--- /dev/null
+++ b/scripts/layer.lua
@@ -0,0 +1,18 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local a = Sprite(32, 64)
+  local l = a.layers[1]
+  assert(l.opacity == 255)
+  assert(l.blendMode == BlendMode.NORMAL)
+
+  l.name = "My Layer"
+  l.opacity = 128
+  l.blendMode = BlendMode.MULTIPLY
+  assert(l.name == "My Layer")
+  assert(l.opacity == 128)
+  assert(l.blendMode == BlendMode.MULTIPLY)
+end
diff --git a/scripts/layers.lua b/scripts/layers.lua
new file mode 100644
index 000000000..95a319c71
--- /dev/null
+++ b/scripts/layers.lua
@@ -0,0 +1,23 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+  assert(#s.layers == 1)
+
+  local a = s.layers[1]
+  local b = s:newLayer()
+  local c = s:newLayer()
+
+  assert(#s.layers == 3)
+  assert(s.layers[1] == a)
+  assert(s.layers[2] == b)
+  assert(s.layers[3] == c)
+
+  s:deleteLayer(b)
+  assert(#s.layers == 2)
+  assert(s.layers[1] == a)
+  assert(s.layers[2] == c)
+end
diff --git a/scripts/palette.lua b/scripts/palette.lua
index f1ea43e82..1c715a9ec 100644
--- a/scripts/palette.lua
+++ b/scripts/palette.lua
@@ -3,7 +3,13 @@
 -- This file is released under the terms of the MIT license.
 -- Read LICENSE.txt for more information.
 
-local p = Palette(32)
+local p = Palette()
+assert(#p == 256)
+for i = 0,#p-1 do
+   assert(p:getColor(i) == Color(0, 0, 0))
+end
+
+p = Palette(32)
 assert(#p == 32)
 for i = 0,#p-1 do
    assert(p:getColor(i) == Color(0, 0, 0))
diff --git a/scripts/slice.lua b/scripts/slice.lua
new file mode 100644
index 000000000..85e62147e
--- /dev/null
+++ b/scripts/slice.lua
@@ -0,0 +1,24 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+
+  local a = s:newSlice(0, 0, 32, 32)
+  assert(a.bounds == Rectangle(0, 0, 32, 32))
+  assert(a.sprite == s)
+
+  assert(a.name == "Slice")
+  a.name = "Slice A"
+  assert(a.name == "Slice A")
+
+  assert(a.center == nil)
+  a.center = Rectangle(2, 3, 28, 20)
+  assert(a.center == Rectangle(2, 3, 28, 20))
+
+  assert(a.pivot == nil)
+  a.pivot = Point(16, 17)
+  assert(a.pivot == Point(16, 17))
+end
diff --git a/scripts/slices.lua b/scripts/slices.lua
new file mode 100644
index 000000000..7895ae497
--- /dev/null
+++ b/scripts/slices.lua
@@ -0,0 +1,19 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+
+  local a = s:newSlice()
+  local b = s:newSlice(0, 2, 8, 10)
+  local c = s:newSlice{ x=0, y=0, width=32, height=32 }
+  assert(a.bounds == nil)
+  assert(b.bounds == Rectangle(0, 2, 8, 10))
+  assert(c.bounds == Rectangle(0, 0, 32, 32))
+
+  s:deleteSlice(b)
+  assert(a == s.slices[1])
+  assert(c == s.slices[2])
+end
diff --git a/scripts/sprite.lua b/scripts/sprite.lua
index b6c4d3988..2474fcd48 100644
--- a/scripts/sprite.lua
+++ b/scripts/sprite.lua
@@ -3,30 +3,61 @@
 -- This file is released under the terms of the MIT license.
 -- Read LICENSE.txt for more information.
 
-local a = Sprite(32, 64)
-assert(a.width == 32)
-assert(a.height == 64)
-assert(a.colorMode == ColorMode.RGB) -- RGB by default
+do
+  local a = Sprite(32, 64)
+  assert(a.width == 32)
+  assert(a.height == 64)
+  assert(a.colorMode == ColorMode.RGB) -- RGB by default
 
--- Crop and resize
-a.selection:select(2, 3, 4, 5)
-a:crop()
-assert(a.width == 4)
-assert(a.height == 5)
-a:resize(6, 8)
-assert(a.width == 6)
-assert(a.height == 8)
-a:crop{x=-1, y=-1, width=20, height=30}
-assert(a.width == 20)
-assert(a.height == 30)
+  -- Crop and resize
+  a.selection:select(2, 3, 4, 5)
+  a:crop()
+  assert(a.width == 4)
+  assert(a.height == 5)
+  a:resize(6, 8)
+  assert(a.width == 6)
+  assert(a.height == 8)
+  a:crop{x=-1, y=-1, width=20, height=30}
+  assert(a.width == 20)
+  assert(a.height == 30)
 
--- Resize sprite setting width/height
-a.width = 8
-a.height = 10
-assert(a.width == 8)
-assert(a.height == 10)
+  -- Resize sprite setting width/height
+  a.width = 8
+  a.height = 10
+  assert(a.width == 8)
+  assert(a.height == 10)
 
-local b = Sprite(4, 4, ColorMode.INDEXED)
-assert(b.width == 4)
-assert(b.height == 4)
-assert(b.colorMode == ColorMode.INDEXED)
+  local b = Sprite(4, 4, ColorMode.INDEXED)
+  assert(b.width == 4)
+  assert(b.height == 4)
+  assert(b.colorMode == ColorMode.INDEXED)
+end
+
+-- Transparent color
+
+do
+  local a = Sprite(32, 32, ColorMode.INDEXED)
+  assert(a.transparentColor == 0)
+  a.transparentColor = 8
+  assert(a.transparentColor == 8)
+end
+
+-- Palette
+
+do
+  local a = Sprite(32, 32, ColorMode.INDEXED)
+  assert(#a.palettes == 1)
+  assert(#a.palettes[1] == 256)
+
+  local p = Palette(3)
+  p:setColor(0, Color(255, 0, 0))
+  p:setColor(1, Color(0, 255, 0))
+  p:setColor(2, Color(0, 0, 255))
+  a:setPalette(p)
+
+  assert(#a.palettes == 1)
+  assert(#a.palettes[1] == 3)
+  assert(a.palettes[1]:getColor(0) == Color(255, 0, 0))
+  assert(a.palettes[1]:getColor(1) == Color(0, 255, 0))
+  assert(a.palettes[1]:getColor(2) == Color(0, 0, 255))
+end
diff --git a/scripts/tag.lua b/scripts/tag.lua
new file mode 100644
index 000000000..a866166d5
--- /dev/null
+++ b/scripts/tag.lua
@@ -0,0 +1,33 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+  for i = 1,7 do s:newFrame() end
+  assert(#s.frames == 8)
+
+  a = s:newTag(1, 8)
+  assert(a.sprite == s)
+  assert(a.fromFrame == 1)
+  assert(a.toFrame == 8)
+  assert(a.frames == 8)
+
+  a.fromFrame = 2
+  a.toFrame = 5
+  assert(a.fromFrame == 2)
+  assert(a.toFrame == 5)
+
+  assert(a.name == "Tag")
+  a.name = "Tag A"
+  assert(a.name == "Tag A")
+
+  assert(a.aniDir == AniDir.FORWARD) -- Default AniDir is FORWARD
+  a.aniDir = AniDir.REVERSE
+  assert(a.aniDir == AniDir.REVERSE)
+  a.aniDir = AniDir.PING_PONG
+  assert(a.aniDir == AniDir.PING_PONG)
+  a.aniDir = AniDir.FORWARD
+  assert(a.aniDir == AniDir.FORWARD)
+end
diff --git a/scripts/tags.lua b/scripts/tags.lua
new file mode 100644
index 000000000..902ffff65
--- /dev/null
+++ b/scripts/tags.lua
@@ -0,0 +1,29 @@
+-- Copyright (C) 2018  David Capello
+--
+-- This file is released under the terms of the MIT license.
+-- Read LICENSE.txt for more information.
+
+do
+  local s = Sprite(32, 32)
+  for i = 1,7 do s:newFrame() end
+  assert(#s.frames == 8)
+
+  a = s:newTag(1, 2)
+  b = s:newTag(3, 4)
+  c = s:newTag(5, 8)
+
+  assert(a.frames == 2)
+  assert(b.frames == 2)
+  assert(c.frames == 4)
+
+  assert(a == s.tags[1])
+  assert(b == s.tags[2])
+  assert(c == s.tags[3])
+
+  s:deleteTag(b)
+  assert(a == s.tags[1])
+  assert(c == s.tags[2])
+
+  assert(c.fromFrame == 5)
+  assert(c.toFrame == 8)
+end