OK, so i'm back with a straighter answer. If a video game is completely linear and short, has barley any options or only a couple of levels, or has a vary small world it's probably worth nothing (free) or slightly more in my opinion.
If it has more depth, a larger world, more options or levels, or un-lockables, (etc) it's would be worth more, if you want to sell a game @seether than research what I said in this post. To find out what something is worth is how big and how many different in-game options it has.
(my example)
In my opinion a fighting game with only 8 or less playable character and no un-lockables. or, not many choose able options. Would be worth less than a fighting game, that has multiple ways of playing, more characters, and more depth.
also something that is playable comes in key with all video games in my opinion also