diff --git a/src/lib/bit.lua b/src/lib/bit.lua
new file mode 100644
index 0000000..d9fd4ce
--- /dev/null
+++ b/src/lib/bit.lua
@@ -0,0 +1,260 @@
+--[[---------------
+LuaBit v0.4
+-------------------
+a bitwise operation lib for lua.
+
+http://luaforge.net/projects/bit/
+
+How to use:
+-------------------
+ bit.bnot(n) -- bitwise not (~n)
+ bit.band(m, n) -- bitwise and (m & n)
+ bit.bor(m, n) -- bitwise or (m | n)
+ bit.bxor(m, n) -- bitwise xor (m ^ n)
+ bit.brshift(n, bits) -- right shift (n >> bits)
+ bit.blshift(n, bits) -- left shift (n << bits)
+ bit.blogic_rshift(n, bits) -- logic right shift(zero fill >>>)
+ 
+Please note that bit.brshift and bit.blshift only support number within
+32 bits.
+
+2 utility functions are provided too:
+ bit.tobits(n) -- convert n into a bit table(which is a 1/0 sequence)
+               -- high bits first
+ bit.tonumb(bit_tbl) -- convert a bit table into a number 
+-------------------
+
+Under the MIT license.
+
+copyright(c) 2006~2007 hanzhao (abrash_han@hotmail.com)
+--]]---------------
+
+do
+
+------------------------
+-- bit lib implementions
+
+local function check_int(n)
+ -- checking not float
+ if(n - math.floor(n) > 0) then
+  error("trying to use bitwise operation on non-integer!")
+ end
+end
+
+local function to_bits(n)
+ check_int(n)
+ if(n < 0) then
+  -- negative
+  return to_bits(bit.bnot(math.abs(n)) + 1)
+ end
+ -- to bits table
+ local tbl = {}
+ local cnt = 1
+ while (n > 0) do
+  local last = math.mod(n,2)
+  if(last == 1) then
+   tbl[cnt] = 1
+  else
+   tbl[cnt] = 0
+  end
+  n = (n-last)/2
+  cnt = cnt + 1
+ end
+
+ return tbl
+end
+
+local function tbl_to_number(tbl)
+ local n = table.getn(tbl)
+
+ local rslt = 0
+ local power = 1
+ for i = 1, n do
+  rslt = rslt + tbl[i]*power
+  power = power*2
+ end
+ 
+ return rslt
+end
+
+local function expand(tbl_m, tbl_n)
+ local big = {}
+ local small = {}
+ if(table.getn(tbl_m) > table.getn(tbl_n)) then
+  big = tbl_m
+  small = tbl_n
+ else
+  big = tbl_n
+  small = tbl_m
+ end
+ -- expand small
+ for i = table.getn(small) + 1, table.getn(big) do
+  small[i] = 0
+ end
+
+end
+
+local function bit_or(m, n)
+ local tbl_m = to_bits(m)
+ local tbl_n = to_bits(n)
+ expand(tbl_m, tbl_n)
+
+ local tbl = {}
+ local rslt = math.max(table.getn(tbl_m), table.getn(tbl_n))
+ for i = 1, rslt do
+  if(tbl_m[i]== 0 and tbl_n[i] == 0) then
+   tbl[i] = 0
+  else
+   tbl[i] = 1
+  end
+ end
+ 
+ return tbl_to_number(tbl)
+end
+
+local function bit_and(m, n)
+ local tbl_m = to_bits(m)
+ local tbl_n = to_bits(n)
+ expand(tbl_m, tbl_n) 
+
+ local tbl = {}
+ local rslt = math.max(table.getn(tbl_m), table.getn(tbl_n))
+ for i = 1, rslt do
+  if(tbl_m[i]== 0 or tbl_n[i] == 0) then
+   tbl[i] = 0
+  else
+   tbl[i] = 1
+  end
+ end
+
+ return tbl_to_number(tbl)
+end
+
+local function bit_not(n)
+ 
+ local tbl = to_bits(n)
+ local size = math.max(table.getn(tbl), 32)
+ for i = 1, size do
+  if(tbl[i] == 1) then 
+   tbl[i] = 0
+  else
+   tbl[i] = 1
+  end
+ end
+ return tbl_to_number(tbl)
+end
+
+local function bit_xor(m, n)
+ local tbl_m = to_bits(m)
+ local tbl_n = to_bits(n)
+ expand(tbl_m, tbl_n) 
+
+ local tbl = {}
+ local rslt = math.max(table.getn(tbl_m), table.getn(tbl_n))
+ for i = 1, rslt do
+  if(tbl_m[i] ~= tbl_n[i]) then
+   tbl[i] = 1
+  else
+   tbl[i] = 0
+  end
+ end
+ 
+ --table.foreach(tbl, print)
+
+ return tbl_to_number(tbl)
+end
+
+local function bit_rshift(n, bits)
+ check_int(n)
+ 
+ local high_bit = 0
+ if(n < 0) then
+  -- negative
+  n = bit_not(math.abs(n)) + 1
+  high_bit = 2147483648 -- 0x80000000
+ end
+
+ for i=1, bits do
+  n = n/2
+  n = bit_or(math.floor(n), high_bit)
+ end
+ return math.floor(n)
+end
+
+-- logic rightshift assures zero filling shift
+local function bit_logic_rshift(n, bits)
+ check_int(n)
+ if(n < 0) then
+  -- negative
+  n = bit_not(math.abs(n)) + 1
+ end
+ for i=1, bits do
+  n = n/2
+ end
+ return math.floor(n)
+end
+
+local function bit_lshift(n, bits)
+ check_int(n)
+ 
+ if(n < 0) then
+  -- negative
+  n = bit_not(math.abs(n)) + 1
+ end
+
+ for i=1, bits do
+  n = n*2
+ end
+ return bit_and(n, 4294967295) -- 0xFFFFFFFF
+end
+
+local function bit_xor2(m, n)
+ local rhs = bit_or(bit_not(m), bit_not(n))
+ local lhs = bit_or(m, n)
+ local rslt = bit_and(lhs, rhs)
+ return rslt
+end
+
+--------------------
+-- bit lib interface
+
+bit = {
+ -- bit operations
+ bnot = bit_not,
+ band = bit_and,
+ bor  = bit_or,
+ bxor = bit_xor,
+ brshift = bit_rshift,
+ blshift = bit_lshift,
+ bxor2 = bit_xor2,
+ blogic_rshift = bit_logic_rshift,
+
+ -- utility func
+ tobits = to_bits,
+ tonumb = tbl_to_number,
+}
+
+end
+
+--[[
+for i = 1, 100 do
+ for j = 1, 100 do
+  if(bit.bxor(i, j) ~= bit.bxor2(i, j)) then
+   error("bit.xor failed.")
+  end
+ end
+end
+--]]
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/main.lua b/src/main.lua
index 9ec3029..f2ecb68 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -12,6 +12,7 @@ ld = love.data
 U = require 'util'
 
 require 'log'
+require 'lib.bit'
 
 local random = require 'randomizer'
 local settings = require 'settings'
diff --git a/src/randomizer.lua b/src/randomizer.lua
index 35cf103..464a408 100644
--- a/src/randomizer.lua
+++ b/src/randomizer.lua
@@ -35,6 +35,7 @@ function C:new()
   self.customseed = nil
   self.puppy = false
   self.obj = ""
+  self.sharecode = ""
 end
 
 function C:setPath(path)
@@ -53,7 +54,11 @@ function C:randomize()
     return "Could not find \"data\" subfolder.\n\nMaybe try dropping your Cave Story \"data\" folder in directly?"
   end
   
+  self:_logSettings()
+
   local seed = self:_seedRngesus()
+  self:_updateSharecode(seed)
+
   local tscFiles = self:_createTscFiles(dirStage)
   -- self:_writePlaintext(tscFiles)
   self:_shuffleItems(tscFiles)
@@ -64,7 +69,7 @@ function C:randomize()
 
   self:_updateSettings()
 
-  return self:_getStatusMessage(seed)
+  return self:_getStatusMessage(seed, self.sharecode)
 end
 
 function C:_mountDirectory(path)
@@ -257,17 +262,57 @@ function C:_unmountDirectory(path)
   assert(lf.unmount(path))
 end
 
+function C:_logSettings()
+  local obj = "Best Ending"
+  if self.obj == "objBadEnd" then
+    obj = "Bad Ending"
+  elseif self.obj == "objNormalEnd" then
+    obj = "Normal Ending"
+  elseif self.obj == "objAllBosses" then
+    obj = "All Bosses"
+  end
+
+  local puppy = self.puppy and ", Puppysanity" or ""
+  logNotice(("Game settings: %s"):format(obj .. puppy))
+end
+
 function C:_updateSettings()
   Settings.settings.puppy = self.puppy
   Settings.settings.obj = self.obj
   Settings:update()
 end
 
-function C:_getStatusMessage(seed)
+function C:_updateSharecode(seed)
+  local settings = 0 -- 0b00000000
+  -- 0bXXXXXPOO
+  -- P: single bit used for puppysanity
+  -- O: two bits used for objective
+  -- X: unused
+
+  if self.obj == "objBadEnd" then
+    settings = bit.bor(settings, 1)
+  elseif self.obj == "objNormalEnd" then
+    settings = bit.bor(settings, 2)
+  elseif self.obj == "objAllBosses" then
+    settings = bit.bor(settings, 3)
+  end
+  if self.puppy then settings = bit.bor(settings, 4) end
+
+  if #seed < 20 then
+    seed = seed .. (" "):rep(20-#seed)
+  end
+
+  local packed = love.data.pack("data", "sB", seed, settings)
+  self.sharecode = love.data.encode("string", "base64", packed)
+
+  logNotice(("Sharecode: %s"):format(self.sharecode))
+end
+
+function C:_getStatusMessage(seed, sharecode)
   local warnings, errors = countLogWarningsAndErrors()
   local line1
   if warnings == 0 and errors == 0 then
-    line1 = ("Randomized data successfully created!\nSeed: %s"):format(seed)
+    line1 = ("Randomized data successfully created!\nSeed: %s\nSharecode: %s"):format(seed, sharecode)
   elseif warnings ~= 0 and errors == 0 then
     line1 = ("Randomized data was created with %d warning(s)."):format(warnings)
   else
@@ -275,7 +320,7 @@ function C:_getStatusMessage(seed)
   end
   local line2 = "Next overwrite the files in your copy of Cave Story with the versions in the newly created \"data\" folder. Don't forget to save a backup of the originals!"
   local line3 = "Then play and have a fun!"
-  local status = ("%s\n%s\n\n%s"):format(line1, line2, line3)
+  local status = ("%s\n%s\n%s"):format(line1, line2, line3)
   return status
 end
 
diff --git a/src/ui/draw.lua b/src/ui/draw.lua
index a5413d1..ba41d25 100644
--- a/src/ui/draw.lua
+++ b/src/ui/draw.lua
@@ -12,19 +12,27 @@ layout:setTheme(require 'lib.luigi.theme.dark')
 settings:setTheme(require 'lib.luigi.theme.dark')
 
 function C:setup()
-  settings.puppy.value = Settings.settings.puppy
-  local obj = Settings.settings.obj
-  if obj == "objBadEnd" then
+  self:loadSettings(Settings.settings.puppy, Settings.settings.obj)
+
+  background = lg.newImage('assets/background.png')
+  self:draw()
+  layout:show()
+end
+
+function C:loadSettings(puppy, obj, seed)
+  settings.puppy.value = puppy
+
+  if obj == "objBadEnd" or obj == 1 then
     settings.bad.value = true
     settings.norm.value = false
     settings.boss.value = false
     settings.best.value = false
-  elseif obj == "objNormalEnd" then
+  elseif obj == "objNormalEnd" or obj == 2 then
     settings.bad.value = false
     settings.norm.value = true
     settings.boss.value = false
     settings.best.value = false
-  elseif obj == "objAllBosses" then
+  elseif obj == "objAllBosses" or obj == 3 then
     settings.bad.value = false
     settings.norm.value = false
     settings.boss.value = true
@@ -36,9 +44,7 @@ function C:setup()
     settings.best.value = true
   end
 
-  background = lg.newImage('assets/background.png')
-  self:draw()
-  layout:show()
+  settings.customseed.value = seed or ""
 end
 
 layout.version.text = 'Cave Story Randomizer [Open Mode] v' .. VERSION
@@ -81,6 +87,13 @@ settings.closeButton:onPress(function()
   layout:show()
 end)
 
+settings.customseed:onChange(function()
+  if #settings.customseed.value > 20 then
+    settings.customseed.value = settings.customseed.value:sub(1, 20)
+  end
+  settings.seedcount.text = ("%s/20"):format(#settings.customseed.value)
+end)
+
 function C:draw()
   lg.draw(background, 0, 0)
   --layout:show()
diff --git a/src/ui/settings.lua b/src/ui/settings.lua
index 5c4409b..41444ef 100644
--- a/src/ui/settings.lua
+++ b/src/ui/settings.lua
@@ -5,7 +5,7 @@ return { style = 'dialog',
       { type = 'label', text = 'Seed' },
       {
         { type = 'radio', group = 'seed', text = 'Use random seed', value = true },
-        { flow = 'y', { type = 'radio', group = 'seed', text = 'Use custom seed', id = 'seedselect'}, { type = 'text', id = 'customseed', width = 150 }, {height = false} }
+        { flow = 'y', { type = 'radio', group = 'seed', text = 'Use custom seed', id = 'seedselect'}, {{ type = 'text', id = 'customseed', width = 200}, flow = 'x', { type = 'label', id = 'seedcount' }}, {height = false} }
       },
       { type = 'label', text = 'Randomization Options' },
       { type = 'check', value = false, id = 'puppy', text = "Puppysanity"},