Games must be fun and engaging. They must be rich in content and complexity giving us a lot to learn. The designers must make sure that the interface does not get in the way. Action games involve hand and eye skill under time pressure, strategy and problem solving. In most action games, we need to drive the characters.
Adventure games are all about exploring, usually under little or no time pressure.
We spend a lot of time looking for things and solving puzzles, most of which take us to other places or broaden the plot. In most adventure games, you don't drive the character. Instead, you click on where you want to go and it takes you there. The most important part of the games is that they must be fun. Even if you have a great idea, if it doesn't have anything to do with our theme, it can't be used.