1. It's Fun And Easy To Build A Custom Map
The Portal 2 Puzzle Maker offers a simple and intuitive editor to create new single player and co-op test chambers that is also compatible with more complex tools like the Portal 2 Authoring Tools or Hammer. That means that in addition to adding new options of those who are more advance in the art of modding, newbies are able to dip in and get started on making new content. The only thing more fun than playing other peoples custom made chambers is being able to create your own and see if people like them or not. For people who are interested in exploring game design, the Puzzle Maker offers one of the best ways to get one's foot in the water. Given the innovation that Valve is known for, it's likely that there is still more to come in the way of DLC in the future that could offer up yet more options and content for players to experiment with. Even if they don't, there's already enough available to ensure that Portal fans will keep the game alive for a good long while.