10 Incredible Video Games You Can't Buy Anymore

Cruelly relegated to "the launcher for that Conker proof-of-concept" status, Project Spark was a game creation tool that predated DREAMS by over six years, and had several significantly superior features to that (also pretty amazing) creator software.

For starters, Project Spark had pretty solid logic, with a robust code editor allowing for custom variables - if it had included a solid array, it would have arguably been on par with some industry-standard framework. It also allowed for pointers, custom animations... even online multiplayer. The suite of options was undeniably powerful, but it came with one absolutely brutal drawback.

Project Spark's learning curve was simply too steep for the vast majority of players, with a knowledge of game development required to really get the best out of it. And, given there was no effective way to collaborate on projects, this meant that beginners were completely out of luck.

Yet, get past that high barrier and you'd be rewarded with an embarrassment of options - some of the user creations included a remarkably solid Call of Duty: Black Ops Zombies clone, tower defense games, and yes... even full levels for Conker.

Despite the amazing results (which we're now seeing repeated in Sony's DREAMS), Microsoft recognised the stratospheric skill requirements to use Project Spark were just too high for most players to push beyond, and axed Spark a few years later.