Ah, the Close Combat series. Over twenty years old, and still disabusing people of the notion that World War 2 was won through heroic charges through enemy fire against improbable odds. The venerable simulationist strategy series has been crushing the spirits of would-be tacticians for a very long time now, although many of the games have been out of circulation for some time.
Presumably in order to raise interest in the upcoming sequel, Close Combat: The Bloody First, GOG have managed to secure the rights to redistribute most of the series, with five games being available to buy DRM-free, and all discounted at present.
I must confess that my experience with the series is limited, although not for want of trying. I've attempted to wrap my head around the tactical subtleties of these games several times, and somehow ended up in the same familiar spiral of broken morale and shattered vehicles each and every time, with each move made to restore my forces turning into a fresh mistake accompanied by further losses.
Being honestly quite rubbish at Close Combat, it's hard for me to rightfully recommend the franchise. Thankfully, you don't have to take my word on the quality of these games - our resident historical strategy boffin Tim Stone has said plenty on the subject, and it's mostly positive. The AI in the games shows its age from time to time, and the interface isn't nearly as smooth and intuitive as it could be by modern standards, but there are still plenty of reasons why the Close Combat name carries weight to this day, and if you're the sort of person who knows their PaK 37 from their QF6's, these might be just what the general ordered.
The Close Combat sale on GOG includes Close Combat's 2 through 4, and the two most recent games, Panthers In The Fog and Gateway to Caen. The latter two (normally priced to fit the strategy grognard market, as per Slitherine's standard rules of engagement) are heavily discounted at present, down a whole 65% off RRP, and the sale will be running for the next six days, give or take. The next game in the series, Close Combat: The Bloody First, is due for release sometime this year after extensive delays.