The Binding of Isaac can be a very tricky game, so knowing these tips can definitely help you in your first play-through.
The first tip is to familiarize yourself with the basic map layout. This will greatly assist you with your playthroughs. Item rooms and shops are found on the first three sets of floors – Basement, Caves, and Depths – and require a key beginning on the second floor. Other than the cost of a key, item rooms typically contain a free item and should always be visited, so save your keys!
My second tip is to make use of deals with the devil. You can do this by getting a Joker card, a Red Chest, or following a boss fight; the deal will appear. If you’re willing to trade away some heart containers with the agreement, you could potentially get some of the strongest items in the game.
My third tip is to look for rocks with markings on them. The best payouts are normally additional soul hearts to bolster your HP or The Small Rock, a good damage-increasing item which is useful to any Isaac run, particularly early.
My fourth tip is to make sure that you’re dodging enemy shots, rather than dealing damage. The vast, vast majority of enemies and bosses have predictable movement and attack patterns, but be aware that they vary widely. Learning these patterns frees you to better select your movement rather than just mashing buttons frantically. Sooner or later, in a run, you’ll find yourself lacking in damage, and the surefire way you’re going to survive will be to dodge.
My fifth tip is to become Guppy the cat. In Afterbirth Plus, picking up three items from certain subsets of items will give you a transformation. The transformations vary widely, but by far the most powerful is becoming Guppy. The Guppy Transformation occurs after the player collects three of the six items in the game themed after a cat owned by developer Edmund McMillen, named Guppy. The Guppy transformation grants the player the ability to fly, an adorable cat player model, and a blue fly is spawned with each tear that hits an enemy. Blue flies then seek out and attack enemies close to your character, dealing 2x your tear damage each.
These are all my tips for TBOI. I hope these help you with your runs.
