[NiGHTS Noob]

Definitely a rental. I don't regret buying it, but if you don't have the money on hand there's no point in saving up for it. Just rent it for a few days and you should be good.

[KennEH!]

Yea I was kinda disappointed on how short it was, but it makes the story much more plausible. Plus I found the combat and sneaking quite enjoyable, making challenge mode have more replay value for me than the guy you linked to.

I'd say rent it though. If anything worthwhile becomes available on DLC, expanding the game, then buy it.

[Master of AFTER]

I don't know, man... I think if you just fly through the game, then yeah, I assume about 7 or 8 hours sounds like enough time to beat it. However, assuming you actually take the time to get some of the bonus collectables, find the best routes through each area, don't skip any of the combat situations, and don't use a walkthrough or a guide to help you with any of the puzzles, then you're probably going to have to sink a bit more time into the game than that. I'm playing the game on normal difficulty and I'm probably pretty close to having racked up eight or so hours of playtime, and I still have two entire buildings left to explore on the island.

Now, if you're going for a 100% completion rating, then you're going to be playing the game for a loooong time.

[KennEH!]

If your looking for an average game time my play time was about 9 hours for everything. Well, except for challenge mode.