Tacoma, the latest game from the creators of Gone Home, is by all reports very good. Our reviewer Andy Kelly wrote as much, deciding that it's "a smart and thoughtful science fiction mystery featuring a cast of believable, nuanced characters." So if that sounds like something you'd be keen on, then GOG has a pretty good deal right now: buy the game there, and you'll get Event free.
By pure coincidence, Andy also reviewed Event when it released late last year, and it's pretty good too. "An imaginative, atmospheric, and cleverly designed sci-fi adventure that’s over far too quickly," he wrote. Seems like if you're a fan of sci-fi games that don't involve murdering aliens en masse, then you might be in luck. Check out the deal over here, and keep in mind the offer is only valid until August 16..