The Kingdoms of Amalur: Reckoning demo, yes I only played it because of the Mass Effect 3 items, but that's what forms the majority of this story.
First time I played it I was vaguely impressed. It was sort of a more serious Fable, the world seemed interesting for a rather standard fantasy fare, but then as I was speaking to the first Fateweaver conversations just disappeared with a lovely bug. However, there was a prize at the end of the road so I pushed on, ran across the play area to see as much of the main quest as I could to see if it grabbed me. It sort of did. But then it happened. It crashed. One of those big ones that freezes the entire Xbox and the only way around it is the power button.
Any other game would have gotten a “Well that's buggy as week old shit” and forgotten, but there was a Mass Effect unlock waiting at the other side. A few days later I had another pop. I had a few hours before I had to head out and figured I had plenty of time to fit in the 45 minutes needed. This was when I realised just how amazing a demo the game was. First I didn't have to redo the tutorial the game just went “Shall I skip that part since you've done it already”, which I thought was going to be the most painful of the replay. That done I set off handling the quests I'd blatantly ignored previously and I was in for another shock. The disappearing conversations were nowhere to be found, and I'd never see them again.
Then the other surprise, the 45 minutes passed and I needed to start getting ready. I shoved it on pause and ran around. With half an hour to go I hoped I had enough time, the clock said less than 20 minutes, I should be fine. When the taxi turned up I still had just under 10 minutes to go. Arse.
The next day, a little hung over and incredibly tired, I was determined to finally get it out the way. I did the four or five quests I'd not got round to and still had over ten minutes to go. I wasted them exploring more of the playable region. Finally I had my Mass Effect 3 unlock. But that wasn't all.
First of all, this is how you make a demo for an open-world RPG. They say 45 minutes of free-roaming. But that's 45 minutes of running and stabbing. Go to the map or inventory, or have a conversation and the clock stops. I reckon barring bugs and that, the first attempt would have easily lasted three hours. Sure you'd eventually hit points in a quest line where it said “You've gone as far as we're letting you” but it was a good taste of things to come and there was always plenty more to see.
The second and third playthroughs totally eclipsed the buggy, less involving first. They immersed me in the world and Kingdoms of Amalur has gone from not even being on my radar to a game I'm trying to figure out a way to afford.