In order to take full advantage of this you'll need a steady source of half red hearts such as Little C.H.A.D. If you don't, the coop baby will die, but since it only had half a hitpoint to begin with, you won't lose additional health. If you manage, you're no worse than you were before.

Occasionally taking half damage after the Womb: if you have, say, just 5½ red hearts and a safe corner to park Isaac in, you can try and complete the room with your coop baby.

If you have the Bible, you can try and clear them anyway and see if, by any chance, the items dropped are good enough to activate temporary flight. If you have Magneto, you can clear fires, poop or laying bombs on marked rocks hidden past metal blocks and then attract the drops over to you. Your coop baby can deploy bombs, pushing items past spikes. If you have a single black or red heart, you can use the co-op buddy to use your heart containers yourself. When you hit start again, these blue hearts go on top of your health bar, providing helpful 'padding' and increasing the chance that they actually damage a boss. When you hit start the first time, some of your blue hearts are transferred to your coop partner. time.) What you can do instead is hitting Start on your controller, collecting the black hearts, then hitting start again. Have a bunch of blue hearts and a black heart is on the ground? If you pick up the black heart directly, it'll go last on your stack of hearts and you might lose it at an inappropriate time, such as right after having cleared a room (and this happens every. I literally beat those challenges while using WASD in a hand and the Start button on my controller in the other.Ĭaveat: Rainbow poop does not heal the co-op buddy.īonus: In Cat Got Your Tongue, your co-op tears make your main player generate flies.

This does require you to have more than one hitpoint to spare for your coop baby. This is especially useful in a few challenges such as The Bean, where your coop partner really is your only source of firepower, or in Solar System, where your coop partner can fire things from a distance (with its own blue attack fly) while Isaac cowers safely in a corner. The no-tear challenges would prevent you from destroying poop or putting fires out, but your coop baby can fire tears normally. It does not work with items like Prayer Card or Book of Revelations. Boom and Yum heart (when co-op baby has a half heart). Some spacebar items will trigger twice in co-op mode.

Here is a number of ways, in increasing order of ridiculousness:

How to play coop in binding of isaac