Deltarune Chapter 4 secret boss guide

Mike’s Room is a unique location you can find in Castle Town in Deltarune, specifically in the TV building. Whether you’re alone or with friends, head inside the TV building, and you’ll eventually find a door with Mike’s name on it. This is Mike’s Room, but you can’t simply walk into it without a hitch. You need Mike’s Room code first.

Mike’s Room code in Deltarune is 6453. However, your code might be a different combination, as the code is linked to the phone numbers you can find in Deltarune Chapter 4. Other numbers we know of that work include 5962, so try this as an alternative if the first combination doesn’t work. When more codes appear, we’ll include them here.

Inside Mike’s Room, you can find multiple cat statues that you can interact with. One statue has cat ears, which you can pet. Another has a mouse at the statue’s feet, which will help you by transforming into a giant hand.

With this hand, you can nab some extra items that were previously out of reach in Mike’s Room. There’s also a treasure box with goodies inside it, too. However, the coolest thing is a crystal ball that takes the form of a microphone. Next to it is another door with Mike’s name on it.

Motormouth Mike is the secret boss in Deltarune Chapter 4, and you can beat him by beating the various minigames you participate in. Now, this boss fight can be a bit tricky, as each stage is different.

Motormouth Mike stage

This is a game of volume, literally. When you enter the applause round, the volume bar will increase to 100, and this is where you need to keep it. Conversely, when the volume reaches zero, it’s time to be quiet, so keep the volume down. When the volume bar is normal, simply dodge the microphones from above and below.

Cat Mike stage

In this stage, you can use the helpful mouse hand from earlier to pet different cats that appear on the screen. Just keep petting them, and you’ll get through to the Bigmouth Mike stage.

Bigmouth Mike stage

Now, you need to dodge cat paws until all three variants of Mike appear. Yes, you have to fight them all at once. Use your mouse hand to fill your basket with kittens, and bring the blue parent cat to it too. Keep doing this, and after some time passes, Bigmouth Mike will form into Merged Mike.

Merged Mike stage

Okay, this is the last stage of the secret boss fight in Deltarune Chapter 4. Keep petting Merged Mike with the mouse hand, and the battle will conclude with most of the Mikes running from the scene. In the following cutscene, Moutmouth Mike reveals that none of these variants are Mike, but they’re just looking after Mike’s Room. Mike was never even here to begin with, and no one knows who he is!

The secret rewards for beating the secret boss in Deltarune Chapter 4 are three special minigames. You can play these minigames by going back to Mike’s Room, and they consist of Pluey, Jongler, and Battat.

Pluey involves picking up blue parent cats and returning them to your basket while avoiding huge raindrops. Jongler is all about throwing cats using the mouse hand into red areas on the screen. Finally, Battat is a minigame where you hit cats with the mouse hand as you move across the right side of the screen. There are bonus points for hitting green cats.