In here you will find the BASIC program for a contest used on
http://reddit.com/r/RetroBattlestations. The program was intended to
be reusable and reasonably portable to many different BASIC
flavors. The "graphics" are character based and have some simple
sprites. It should be portable to any BASIC that has the ability to
position the cursor at a specific location.

Don't have a retro computer and don't want to figure out how to setup
an emulator? Try the Apple II version in your browser:
http://retrobattlestations.com/AppleII/HalloweenBoogaloo.shtml

=== Typing Tips ===
When typing the program in you can leave off any lines which contain
REM, they are not needed for the program to run. You can also leave
out all whitespace.

Note: On the TRS-80 Color Computer and BBC Micro you need to include
      the spaces around any IF, AND, OR, or THEN statement.

If you make a mistake and don't want to retype the entire line, most
of the BASICs have a way to make corrections.

Apple II computers:
  On an Apple II+ use LIST <line number> to print the line with an
  error, then use ESC followed by A/B/C/D to move the cursor one step
  at a time. Position the cursor at the beginning of the line, then
  use the right arrow to move over the line and fix the error. Be sure
  to arrow all the way to the end of the entire line before you hit
  RETURN!

  On an enhanced Apple IIe, Apple IIc, or Apple IIgs you can also use
  ESC with the arrow keys. In 80 column mode (enter with PR#3) the
  cursor will change to a white block with a + in it, push ESC to drop
  out of movement mode.

BBC Micro:
  Use LIST <line number> to print the line with a mistake, then use
  the arrow keys to move up to the beginning of the line. Each press
  of the copy key will type in the character under the cursor. Make
  any necessary edits by just typing on the keyboard and using copy to
  avoid retyping everything.

Commodore 64 and Plus/4:
  Like the others, use LIST <line number> to display the line with
  problems, then use the arrow keys to move up and make any
  corrections. By pressing shift-INST you can insert a blank character
  if you missed something. Unlike the Apple II you don't need to arrow
  to the end of the line before pushing RETURN.

TRS-80 model 100:
 This has to be the best built-in BASIC editor I've seen so far! Just
 type EDIT and the entire BASIC program will be loaded into the
 built-in word processor where you can make any changes you
 want. Press F8 to exit the editor and go back to BASIC.