The Binding of Isaac: Rebirth has been a long time coming on Wii U, but it was worth the wait. With excellent enemy and boss variety along with a seemingly endless supply of pickups and items to help Isaac escape his mom's horrifying basement, the game constantly surprises players with something new. The only thing you'll see repeatedly is poor Isaac's corpse, as this randomly-generated roguelike is viciously difficult. Still, you'll likely be hammering the retry button before the boy's spirit has left his body, itching to have another go at this ridiculous, sickening, funny game.

Rebirth's stages look like someone smeared excrement all over The Legend of Zelda. Using a top-down view similar to Zelda, you're able to see a single room at a time, with doors leading to new rooms sticking out of the sides. No peeking at what's coming next! You have to go into each area blind, relying on reflexes to deal with what's inside. The in-game map does indicate special kinds of rooms, though, so you'll know if you're wandering into an enemy challenge room or treasure chamber if you pay attention. As for regular enemy rooms, you're on your own. Don't try to memorize the dungeon layouts, either, as they're randomly-generated when you start up the game. Each new run is a surprise.

Once inside a room, expect to fight something gross. The monsters in Rebirth all seem to be composed of rotting, diseased flesh, bulging with sores and quivering with agony. They cry, scream, and roar as they march toward you, every movement seeming to bring them pain. They sound horrifying on paper, but they're all just a bit cute as well. The enemies are messed-up, but the game's art style ensures that they don't look too menacing or disgusting. The style is light, injecting some humour into what should be an extremely dark, troubling game. It's a perfect combination, allowing the developers to design some sickening, monstrous beasts while making them look just silly enough that they won't turn someone's stomach.

There are dozens of monsters for you to run into as the game cobbles the rooms together for your run. You'll see a lot of them many times, but on most runs expect to trip over at least one new creature you haven't seen before. There is a lot of variety in enemy design as well as in their abilities and movements in combat, so even after putting in hours of play you'll still be learning new enemy attacks. A lot of effort has gone into ensuring you have many new things to fight on each run through the dungeon, keeping players from getting so familiar with combat that they always know what to do.

Still, you've got to get rid of these beasts if you want to live long, as each room locks you in once enemies appear. What's a little boy to do? Cry about it. For whatever reason, Isaac's tears are weaponized, allowing him to cry so hard that his thrown tears damage and kill these abominations. You can cry up, down, left, or right, blasting your enemies with sadness until they crumble into bloody chunks. It can feel very limiting to only fire in those directions, and in some instances combat seems to be begging to be able to fire on a diagonal. It would certainly make things a lot easier in many of the game's harder rooms.

That would have required an overhaul of how the game challenges the player, though. The rooms have been filled with obstacles that put the player onto certain paths, and enemies move and attack in ways that force utilisation of the terrain for protection, or to lure enemies into the line of fire. The game is built around smart movement and positioning, and diagonal fire would have undermined that. As is, it cleverly sows enemies and obstacles throughout the room, creating chambers that are also small puzzles that must be solved in moments. If you're fighting this enemy with that layout, how can you move so that the enemy follows you in such a way that you can hit them? This thinking is what let the developers create some crushing, yet extremely satisfying, challenge in the game.

It can still be difficult to hit your enemies even with this system, though. Hit detection can be a little dodgy in places, as some of your tears will drift through enemy sprites on the sides, requiring you hit them more toward the centre to register damage. It's something that isn't a problem all that often, but when you're being dogged by half a dozen spiders, watching a shot pass just a little too far to the side and miss can be frustrating. You can fire so quickly that it doesn't matter much, but when death is permanent it can be aggravating to see shots miss that you thought would hit. It's a bit too precise given the fast-paced nature of the game, but it's something you get used to and account for.

The player isn't entirely without help, though. There are hundreds upon hundreds of item pickups that you can grab, each changing some aspect of your health or attacks (and all of them stack). At first, these upgrades do simple things like improve damage or range, but later items give Isaac abilities that let him charge up a form of invincibility while running around, cast off poisonous clouds with every tear, or attack enemies with helpful flies. When you find a treasure room you feel genuinely excited as there are just so many new things to find, even after hours and hours of play. Not only that, but since these powers are so varied, they each change the way you play the game, making each new run wildly different from the last. These powers force you to re-invent your play style constantly, keeping the game fresh even after dozens of runs.

These powers have interesting effects on Isaac's appearance as well, changing his character into something more fitting for the environment. He may get glassy-eyed, he might develop a growth on his face, or horns may shoot out of his head depending on which pickup you find. They add a visual appeal to getting a new item along with the new power, leaving players wondering how all of their new, weird growths will look together. This also seems to be a hint of wordless storytelling as well, as Isaac becomes more monstrous with each new power. He starts to bear similarities to his enemies as he grows stronger, leaving the player to wonder if that may have something to do with all of the gross monsters down here. Is he on the path to meeting a similar fate?

Still, what if you really liked a power you got, but died? You only get one life in this roguelike, but the game provides a code, called a Seed, on each run through the dungeon. If you like the items you picked up during it, you can write the Seed down (it's a simple eight character code) and then input it on a new run. This will keep the items in the locations you found them, meaning you can take another shot at the dungeon with the ability to gather the same group of powers again. It's a nice touch if you have a great run using a certain item set, and will help starting players get a little more practice if they wish to take some of the randomness out of the game.

If you've played it to death and want more challenge, though, the game provides specific challenge runs to test expert players. You may have to play with most of the stage in the dark or fight with a limited power that attacks in strange ways. These add new, difficult challenges for anyone who feels that Rebirth's variety has started to grow stale. That won't happen for a while given the sheer amount of possible items you can get and the game's high difficulty, but for true Rebirth fanatics these challenges will keep you playing the game long after you thought you were done. If they don't work, you can always try for the extra characters, each of whom has some difficult unlock conditions.

Conclusion

The Binding of Isaac: Rebirth has some minor issues with combat, but excellent enemy variety, in both their design and combat abilities, makes every new run a different challenge. With so many items added to the mix, each run at the dungeon becomes unique, making Rebirth feel like a new game every time you start it up. It's gross, but also funny, striking up a great balance between discomfort and fun that gives its visuals an interesting appeal. All of its various elements just click together well, creating a solid game that will be hard to put down as you struggle your way to the deepest recesses of Isaac's basement.