To the Moon isn't a game in a traditional sense. From the looks of it you would expect a point and click adventure game, but there are no puzzles. The game basically plays itself, you just need to click on stuff to make progress. So, is the story good enough to justify complete lack of gameplay? It's ok I guess, but derivative - it has Eternal Sunshine of the Spotless Mind and Inception written all over it. Given a good scenario, this plot could have been material for a decent movie, but it fails as a game. Definitely not worth those 10$.
This is a bad game. The puzzles are easy i predictable, you have access to maximum of 4-5 locations/screens at a given time, so there isn't much room to get stuck. The story isn't bad, but the beginning of the adventure is long and the ending seems rushed (you get to 'save the world' for like 30 minutes). If you want to play a "comedy-fantasy" kind of thing you should choose Simon the Sorcerer 2, I guess it is quite hard by todays standards, but even using the walkthrough you'll have much more fun. If you just want a good adventure game, there are dozens of better choices, even if you a beginner. Don't get me wrong, it's not like that one is unplayable. The problem is you forget about it and the characters in it about 5 minutes after you finished it.
This one is definitely worth buying. The graphics didn't age all that good, the combat system feels old and primitive, BUT the game is VERY long, the puzzles and level design are excellent and as a whole it's a really nice experience. The story is ok, we get four different playable characters, using their skills simultaneously is fun, especially when they get separated. You get some shooting action, but if that's what you're looking go buy something else - this one is more like "Right, so I shot all the baddies, now what are this switches supposed to do?" Perhaps not a must have, but you get a lot of game for your 5.99$.