A 2048 clone for those who can't afford a desktop environment. Runs in sh!

2048.sh

#!/bin/sh
print_cell()
{
	if [ "$1" = 0 ]; then
		echo -en "    "
	else
		if [ "$1" -ge 128 ]; then
			echo -en '\x1B[33m'
		elif [ "$1" -ge 16 ]; then
			echo -en '\x1B[31m'
		fi
		pad="$1"
		while [ "${#pad}" != 4 ]; do
			pad=" $pad"
		done
		echo -en "$pad"'\x1B[0m'
	fi
}

print_row()
{
	print_cell "$1"
	echo -en ' '
	print_cell "$2"
	echo -en ' '
	print_cell "$3"
	echo -en ' '
	print_cell "$4"
	echo
}

print_board()
{
	print_row "$1" "$2" "$3" "$4"
	print_row "$5" "$6" "$7" "$8"
	print_row "$9" "${10}" "${11}" "${12}"
	print_row "${13}" "${14}" "${15}" "${16}"
}

clear_board()
{
	echo -en '\x1B[1A\x1B[2K'
	echo -en '\x1B[1A\x1B[2K'
	echo -en '\x1B[1A\x1B[2K'
	echo -en '\x1B[1A\x1B[2K'
}

precollapse_row()
{
	while [ "$#" != 0 ]; do
		if [ "$1" != 0 ]; then
			echo "$1"
		fi
		shift
	done
}

collapse_row()
{
	while [ "$#" != 0 ]; do
		a="$1"
		shift
		if [ "$a" = "$1" ]; then
			echo "$(($a*2))"
			shift
		elif [ "$a" != 0 ]; then
			echo "$a"
		fi
	done
}

adjust_four()
{
	echo "$1" "$2" "$3" "$4"
}

collapse_board()
{
	adjust_four $(collapse_row $(precollapse_row "$1" "$2" "$3" "$4")) 0 0 0 0
	adjust_four $(collapse_row $(precollapse_row "$5" "$6" "$7" "$8")) 0 0 0 0
	adjust_four $(collapse_row $(precollapse_row "$9" "${10}" "${11}" "${12}")) 0 0 0 0
	adjust_four $(collapse_row $(precollapse_row "${13}" "${14}" "${15}" "${16}")) 0 0 0 0
}

flip_board()
{
	echo "$4" "$3" "$2" "$1"
	echo "$8" "$7" "$6" "$5"
	echo "${12}" "${11}" "${10}" "$9"
	echo "${16}" "${15}" "${14}" "${13}"
}

transpose_board()
{
	echo "$1" "$5" "$9" "${13}"
	echo "$2" "$6" "${10}" "${14}"
	echo "$3" "$7" "${11}" "${15}"
	echo "$4" "$8" "${12}" "${16}"
}

id()
{
	echo "$1" "$2" "$3" "$4" "$5" "$6" "$7" "$8" "$9" "${10}" "${11}" "${12}" "${13}" "${14}" "${15}" "${16}"
}

count_slots()
{
	count=0
	while [ "$#" != 0 ]; do
		if [ "$1" = 0 ]; then
			count="$(($count+1))"
		fi
		shift
	done
	echo "$count"
}

randomly_place()
{
	slots="$(count_slots "$@")"
	while [ "$#" != 0 ]; do
		if [ "$1" = 0 ]; then
			if [ "$(($RANDOM%$slots))" = 0 ]; then
				if [ "$(($RANDOM%10))" == 0 ]; then
					echo 4
				else
					echo 2
				fi
				shift
				echo "$@"
				return
			else
				slots="$(($slots-1))"
				echo "$1"
			fi
		else
			echo "$1"
		fi
		shift
	done
}

check_win()
{
	while [ "$#" != 0 ]; do
		if [ "$1" = 2048 ]; then
			return 0
		fi
		shift
	done
	return 1
}

board="$(randomly_place 0 0 0 0  0 0 0 0  0 0 0 0  0 0 0 0)"
print_board $board

trap "stty echo; exit" EXIT INT TERM
stty -echo
while true; do
	board="$(randomly_place $board)"
	clear_board
	print_board $board
	if check_win $board; then
		echo "You won"
		exit
	fi
	board_left="$(collapse_board $board)"
	board_right="$(flip_board $(collapse_board $(flip_board $board)))"
	board_up="$(transpose_board $(collapse_board $(transpose_board $board)))"
	board_down="$(transpose_board $(flip_board $(collapse_board $(flip_board $(transpose_board $board)))))"
	if [ "$(id $board)" = "$(id $board_left)" -a "$(id $board)" = "$(id $board_right)" -a "$(id $board)" = "$(id $board_up)" -a "$(id $board)" = "$(id $board_down)" ]; then
		echo "You lost"
		exit
	fi
	old_board="$board"
	while [ "$(id $board)" = "$(id $old_board)" ]; do
		read -n1 c
		if [ "$c" == $'\e' ]; then
			read -n1 c
			if [ "$c" == '[' ]; then
				read -n1 direction
				case "$direction" in
					A) board="$board_up" ;;
					B) board="$board_down" ;;
					C) board="$board_right" ;;
					D) board="$board_left" ;;
				esac
			fi
		fi
	done
done

When executing, it just says:

2048.sh: 177: read: Illegal option -n
2048.sh: 178: [: unexpected operator

Works with bash/zsh though