User-created content has always been one of the best parts of PC gaming. I can't tell you how many map packs, mods, and conversions I've downloaded and enjoyed over the years. As one might expect, I'm rather pleased to see that community site Thinking With Portals has rounded up a collection of the top 25 entries in its summer mapping initiative.
The Portal 2 maps include a mix of levels designed for coop and single-player experiences, and some of them look very slick. Rock, Paper, Shotgun has played a few of the maps and felt that one in particular was more of a complete chapter than a single test. The site also points out that the scale of many of the maps interferes with the puzzle-solving aspect of the game, especially when lasers are involved.
At the same time, RPS notes that Valve's decision to force Portal 2 mappers to use existing in-game assets means that all the user-generated maps fit in nicely with the rest of the game. The community is only a few months into map development, so I'd expect the quality of levels to rise over time—and the number of map packs to increase. I'm not sure I'll make a second run through Portal 2's single-player or even coop campaigns, but when the yearn to test strikes, it's nice to know there are plenty of fresh chambers lying in wait.