View difference between Paste ID: YpAy5Xey and Z7mGQ6XK

 -- Display the start screen
 local w,h = term.getSize()
 
 local titleColour, headingColour, textColour, wormColour, fruitColour
 if term.isColour() then
     titleColour = colours.red
 	headingColour = colours.yellow
 	textColour = colours.white
 	wormColour = colours.green
 	fruitColour = colours.red
 else
     titleColour = colours.white
 	headingColour = colours.white
 	textColour = colours.white
 	wormColour = colours.white
 	fruitColour = colours.white
 end
 
 local function printCentred( y, s )
 	local x = math.floor((w - string.len(s)) / 2)
 	term.setCursorPos(x,y)
 	--term.clearLine()
 	term.write( s )
 end
 
 local xVel,yVel = 1,0
 local xPos, yPos = math.floor(w/2), math.floor(h/2)
 local pxVel, pyVel = nil, nil
 
 local nLength = 1
 local nExtraLength = 6
 local bRunning = true
 
 local tailX,tailY = xPos,yPos
 local nScore = 0
 local nDifficulty = 2
 local nSpeed, nInterval
 
 -- Setup the screen
 local screen = {}
 for x=1,w do
 	screen[x] = {}
 	for y=1,h do
 		screen[x][y] = {}
 	end
 end
 screen[xPos][yPos] = { snake = true }
 
 local nFruit = 1
 local tFruits = {
 	"A", "B", "C", "D", "E", "F", "G", "H",
 	"I", "J", "K", "L", "M", "N", "O", "P",
 	"Q", "R", "S", "T", "U", "V", "W", "X",
 	"Y", "Z",
 	"a", "b", "c", "d", "e", "f", "g", "h",
 	"i", "j", "k", "l", "m", "n", "o", "p",
 	"q", "r", "s", "t", "u", "v", "w", "x",
 	"y", "z",
 	"1", "2", "3", "4", "5", "6", "7", "8", "9", "0",
 	"@", "$", "%", "#", "&", "!", "?", "+", "*", "~"
 }
 
 local function addFruit()
 	while true do
 		local x = math.random(1,w)
 		local y = math.random(2,h)
 		local fruit = screen[x][y]
 		if fruit.snake == nil and fruit.wall == nil and fruit.fruit == nil then
 			screen[x][y] = { fruit = true }
 			term.setCursorPos(x,y)
 			term.setBackgroundColour( fruitColour )
 			term.write(" ")
 			term.setBackgroundColour( colours.black )
 			break
 		end
 	end
 
 	nFruit = nFruit + 1
 	if nFruit > #tFruits then
 		nFruit = 1
 	end
 end
 
 local function drawMenu()
 	term.setTextColour( headingColour )
 	term.setCursorPos(1,1)
 	term.write( "SCORE " )
 
 	term.setTextColour( textColour )
 	term.setCursorPos(7,1)
 	term.write( tostring(nScore) )
 
 	term.setTextColour( headingColour )
 	term.setCursorPos(w-11,1)
 	term.write( "DIFFICULTY ")
 
 	term.setTextColour( textColour )
 	term.setCursorPos(w,1)
 	term.write( tostring(nDifficulty or "?") )
 
 	term.setTextColour( colours.white )
 end
 
 local function update( )
 	local x,y = xPos,yPos
 	if pxVel and pyVel then
 		xVel, yVel = pxVel, pyVel
 		pxVel, pyVel = nil, nil
 	end
 
 	-- Remove the tail
 	if nExtraLength == 0 then
 		local tail = screen[tailX][tailY]
 		screen[tailX][tailY] = {}
 		term.setCursorPos(tailX,tailY)
 		term.write(" ")
 		tailX = tail.nextX
 		tailY = tail.nextY
 	else
 		nExtraLength = nExtraLength - 1
 	end
 
 	-- Update the head
 	local head = screen[xPos][yPos]
 	local newXPos = xPos + xVel
 	local newYPos = yPos + yVel
 	if newXPos < 1 then
 		newXPos = w
 	elseif newXPos > w then
 		newXPos = 1
 	end
 	if newYPos < 2 then
 		newYPos = h
 	elseif newYPos > h then
 		newYPos = 2
 	end
 
 	local newHead = screen[newXPos][newYPos]
 	term.setCursorPos(1,1);
 	print( newHead.snake )
 	if newHead.snake == true or newHead.wall == true then
 		bRunning = false
 
 	else
 		if newHead.fruit == true then
 			nScore = nScore + 10
 			nExtraLength = nExtraLength + 1
 			addFruit()
 		end
 		xPos = newXPos
 		yPos = newYPos
 		head.nextX = newXPos
 		head.nextY = newYPos
 		screen[newXPos][newYPos] = { snake = true }
 
 	end
 
 	term.setCursorPos(xPos,yPos)
 	term.setBackgroundColour( wormColour )
 	term.write(" ")
 	term.setBackgroundColour( colours.black )
 
 	drawMenu()
 end
 
 -- Display the frontend
 term.clear()
 local function drawFrontend()
 	--term.setTextColour( titleColour )
     --printCentred( math.floor(h/2) - 4, " W O R M " )
 
 	term.setTextColour( headingColour )
 	printCentred( math.floor(h/2) - 3, "" )
 	printCentred( math.floor(h/2) - 2, " SELECT DIFFICULTY " )
 	printCentred( math.floor(h/2) - 1, "" )
 
 	printCentred( math.floor(h/2) + 0, "            " )
 	printCentred( math.floor(h/2) + 1, "            " )
 	printCentred( math.floor(h/2) + 2, "            " )
 	printCentred( math.floor(h/2) - 1 + nDifficulty, " [        ] " )
 
 	term.setTextColour( textColour )
 	printCentred( math.floor(h/2) + 0, "EASY" )
 	printCentred( math.floor(h/2) + 1, "MEDIUM" )
 	printCentred( math.floor(h/2) + 2, "HARD" )
 	printCentred( math.floor(h/2) + 3, "" )
 
 	term.setTextColour( colours.white )
 end
 
 drawMenu()
 drawFrontend()
 while true do
 	local e,key = os.pullEvent( "key" )
 	if key == keys.up or key == keys.w then
 		-- Up
 		if nDifficulty > 1 then
 			nDifficulty = nDifficulty - 1
 			drawMenu()
 			drawFrontend()
 		end
 	elseif key == keys.down or key == keys.s then
 		-- Down
 		if nDifficulty < 3 then
 			nDifficulty = nDifficulty + 1
 			drawMenu()
 			drawFrontend()
 		end
 	elseif key == keys.enter then
 		-- Enter
 		break
 	end
 end
 
 local tSpeeds = { 5, 10, 25 }
 nSpeed = tSpeeds[nDifficulty]
 nInterval = 1 / nSpeed
 
 -- Grow the snake to its intended size
 term.clear()
 drawMenu()
 screen[tailX][tailY].snake = true
 while nExtraLength > 0 do
 	update()
 end
 addFruit()
 addFruit()
 
 -- Play the game
 local timer = os.startTimer(0)
 while bRunning do
 	local event, p1, p2 = os.pullEvent()
 	if event == "timer" and p1 == timer then
 		timer = os.startTimer(nInterval)
 		update( false )
 
 	elseif event == "key" then
 		local key = p1
 		if key == keys.up or key == keys.w then
 			-- Up
 			if yVel == 0 then
 				pxVel,pyVel = 0,-1
 			end
 		elseif key == keys.down or key == keys.s then
 			-- Down
 			if yVel == 0 then
 				pxVel,pyVel = 0,1
 			end
 		elseif key == keys.left or key == keys.a then
 			-- Left
 			if xVel == 0 then
 				pxVel,pyVel = -1,0
 			end
 
 		elseif key == keys.right or key == keys.d then
 			-- Right
 			if xVel == 0 then
 				pxVel,pyVel = 1,0
 			end
 
 		end
 	end
 end
 
 -- Display the gameover screen
 term.setTextColour( headingColour )
 printCentred( math.floor(h/2) - 2, "                   " )
 printCentred( math.floor(h/2) - 1, " G A M E   O V E R " )
 
 term.setTextColour( textColour )
 printCentred( math.floor(h/2) + 0, "                 " )
 printCentred( math.floor(h/2) + 1, " FINAL SCORE "..nScore.." " )
 printCentred( math.floor(h/2) + 2, "                 " )
 term.setTextColour( colours.white )
 
 local timer = os.startTimer(2.5)
 repeat
 	local e,p = os.pullEvent()
 	if e == "timer" and p == timer then
 		term.setTextColour( textColour )
 		printCentred( math.floor(h/2) + 2, " PRESS ANY KEY " )
 		printCentred( math.floor(h/2) + 3, "               " )
 		term.setTextColour( colours.white )
 	end
 until e == "char"
 
 term.clear()
 term.setCursorPos(1,1)