When a demo is done properly, it can create a lot of buzz around an unheralded title. The early days saw Fight Night Round 3 stun 360 owners with its sharp visuals and crunching slow-mo knockout replays.
Later down the line Civilization Revolution, Lost Planet, Bioshock and Burnout Paradise all had stellar demos that did a great job of selling the game in question.
Sometimes it's too easy for developers to fall into a "here's the boss, now the demo ends" trap. Unfortunately, some developers tend to fall even further. Here are the five most disappointing demos, all notable for the fact that they've turned people off the game rather than onto it. They might be free but sometimes, you get what you pay for...
5. Battlefield 2: Modern Combat
We're no experts in the field of games development but if you want players to try the online side of your game, then it's best make sure an online-only demo works online.
When Battlefield 2: Modern Combat's demo arrived in the early months of Xbox 360's life, it got off on the wrong foot as it was near impossible to connect to a game. Those who did connect, often after an hour of trying, would get one match in before being booted back to the same menu and forced to endure the same reconnecting ritual for hours and hours.
These problems didn't peter out until a week after the demo had hit Marketplace, by which time the curious had given up and the fans were furious. The game itself was surprisingly good fun but its unique mix of arcade scoring, team tactics and squad gameplay never really ignited in the way it should.
Regardless, it could be argued that the demo was indicative of the final game. Servers that would randomly crash, a clan feature that never worked properly, a health crate bug that drove players away in droves. Modern Combat 2 was a fun game but one that never felt like anything more than a half-hearted nod towards the 360's existence and that all started with the demo.
4. Sonic The Hedgehog
It was supposed to be a glorious rebirth of an old, wayward icon. Sonic has struggled to recapture the glory of his 2D heyday since leaving the Megadrive behind but that was all going to change with this game, promised Sega. A simple title, a new beginning, a new Sonic.
After the tepid Shadow The Hedgehog and Sonic Heroes, Sega had carefully and meticulously crafted some momentum for this latest addition to the series. And then, with the arrival of one terrible demo, all that momentum was stopped.
Sonic The Hedgehog suffered from the same problems all 3D Sonic games had. Uncontrollable. Unplayable. Uneventful. The sensitive controls and linear level felt like you were trying to guide a marble down a hair, with the camera whizzing round doing as it pleases and the limited lives making it a frustrating demo to play through.
Sega went full speed ahead with its damage limitation plans, spreading word that the demo was based was an old build and the final game was much, much better. Yet when the game itself was released, it didn't take long for word to spread that it wasn't different. At all. Having had their fingers burnt on the demo, most Sonic fans decided to sit this one out.
3. Turning Point: Fall of Liberty
What had happened if a road accident Winston Churchill had suffered while in New York had turned out to be fatal? That is the question Turning Point: Fall of Liberty asks before embarking on an alternative timeline where the Nazis are running rampant through World War II New York.