The "real" version of Fate Reawakened, available on that other store, contains all four Fate games in one remastered package. The release here only has the first game, and there are no guarantees that the remaining games will be made available in the future. That means this is not truly Fate Reawakened, but a demo you have to pay for. Why GOG allowed this release to happen is inexplicable. Stay away until/unless the publisher fixes this and releases the actual full game.
A lot of people were disappointed by this game because they wanted it to be a spiritual sequel to Vampire The Masquerade Bloodlines. This is nothing of the sort. It's its own thing, and a very fantastic and atmospheric action-adventure featuring an interesting premise and pretty fun, if very difficult combat. That combat is clearly inspired by Dark Souls, with an emphasis on positioning and timing of attacks but, unlike Dark Souls, you can't grind your way to victory here. There is an experience system, but you get very little XP from combat, and even if you kill all the NPCs in the game (which is your primary means of gaining XP) and max out your character, you won't be able to steamroll the battles.... Unless, that is, you figure out the best tool for the job. There are a couple weapons available that will make every battle a breeze, to the point that even a person like me, who sucks at Dark Souls style games and plays every game on the easiest difficulty available, could get through a pacifist run of the game. That might sound like a bad thing, but I love games that give players tools to tailor the difficulty to their liking. If you want an easy experience, you can use one of the overpowered weapons; if you want a more difficult experience, use one of the many others. Either way, you can experience all the content in the game regardless of your skill level, which is awesome in my book.