Content-wise: Yes, this game has no objectional content whatsoever, so kids 6- could definitely play and watch this game content-wise. However, there is absolutely no way they could survive in this game for more than a few seconds, and they'll probably want to quit playing it even before that happens. I'll explain more in the next category.

Difficulty-wise: When you first start out, there are three branching paths and a cave visible on screen. When you enter the cave, an old man tells you it's dangerous out there and to take this sword. You do, and now you're equipped with the sword and a shield--yeah, thanks, great; lot's of help. If you're at full health you'll be able to "throw" a limitless projection of your sword at enemies, but if you get hit once, the ability's gone until you're fully healed.

After you've figured out the main mechanics (which pretty much consists of one button for attack, the other for whatever) the easy stuff ends there. The base gameplay has you run across screens from an overhead perspective, while fending off an unlimited number of enemies--yes that's right, they will never stop coming. To top it all off, there is absolutely no directions for where to go next (whatsoever), and you die in 6 hits.

This is all the kids had to play in 1987, and they were used to the difficulty their generation of games presented. But kids today are wimps when it comes to games of this type of difficulty (me too!). But (at minimum), I could see some really skilled (and patient!) kids 10+ figure it out (if they time travel from 1987 ;P).

Fun for: The majority of people who are going to rebuy this game are adults who remember it, and actually think they have a chance of completing it. And that's fine, because if you can handle the difficulty, it has the same overlying gameplay that makes the new ones so great.