Aight, got a few points to hit here. First: this game, sans DLC, is still a complete experience. This is not a title for which you *need* to purchase DLC. I loved it when it originally came out, and I have loved every version of it since just as much. Second: Many other reviews advise you to avoid purchasing this game on GOG because the developers have not updated the latest DLC despite updates on Steam. They also mention a missing Daily Challenge feature that's present on Steam. If you want to follow that advice on principle, sure -- do as you wish. But The Binding of Isaac: Rebirth, as I said, is a complete experience, and shouldn't have any version differences from Steam. (Daily Challenges were only added in the first DLC, and they weren't required for achievements until the second DLC.) It's been a long, long time since I played plain Rebirth, so my memory of the particulars is vague, but the fundamentals have always remained the same: the game is a top-down, WASD+arrows shooter with a variety of enemies that follow individually simple, predictable patterns. You collect consumables (coins, bombs, and keys) and items (permanent power-ups) that randomly (and predictably) spawn throughout the game. When you first play, you will probably be at the mercy of luck, and you will die repeatedly, because HP is limited (you have six hits to start) and you haven't seen the types of enemies enough to predict their behavior. But soon, you'll get comfortable with the first two floors and their villains, and you'll graduate to dying on the next two floors. And you'll find particular items that make you feel powerful, and change your gameplay in a way you like. And when you get a very powerful synergy, you'll absolutely crush Mom, the final boss on floor 6 -- huzzah! finally! -- only to be told that the end of the game is now floor 8. And you'll chase that high again. And you'll feel it, more and more. If you can roll with the intial punches, you will love this game.
