If the goal is to teach programming concepts and have a fun time, then by all means look into "COREWAR Dewdney". Do a search on those + keyword. Read the Wikipedia article. I started my kids on a few games that I created (text based & boring) Then went to the 1984 original Dewdney version. I recommend starting kids on a version close to the original (a simpler assembler-like language and with fewer operands). The original version runs, and is over in an eye-blink. I made a version that ran under Power Basic and allowed a slowed down, blow-by-blow view of the progress of the battle. This helped the kids see where their programs strengths & weaknesses were.