Just finished playing Factum solus, a Portal mod. This is the first episode, not entirely sure how many there will be total.
Really enjoyed this mod, one of the best I've played. Very inventive ideas, both in the puzzles and the overall story and the way it was told. I can't really give away too much, but it will move in directions you won't expect.
The puzzles weren't extremely challenging, but I prefer that to them being overly frustrating. They did follow the Portal theme of not being too hard to execute once the solution was actually figured out. Also, since this is the first episode, I expect the later episodes to have much more challenging puzzles as the story becomes deeper.
I've heard some people have experienced quite a few bugs in a few sections. While I didn’t experience any of these bugs mentioned by others, it is still disappointing to read about them. It’s obvious a lot of work went into the design of this mod, it’s a shame to see there wasn’t so much put into the execution and testing.
I'm definitely looking forward to the rest. Definitely worth checking out.