Minigame
They have no effect on anything, so just enjoy yourself and relax!
Minigames (JP: ミニゲーム) are special gameplay segments in Deltarune, introduced in Chapter 3. They often serve to provide a break between standard gameplay segments. Many minigames are optional, but some must be completed to advance the story.
Minigames take on a variety of gameplay styles, each with different win and lose conditions. Each minigame is centered around one unique gimmick, and the objective is often to achieve the highest score possible.
These minigames were introduced in Chapter 3.

TV Time is a collection of minigames hosted by Tenna. It is split into multiple rounds, each consisting of a board from The Legend of Tenna followed by a "physical challenge". These minigames are eventually replayed during the battle against Tenna near the end of the Chapter.
The Legend of Tenna is the primary portion of each round of TV Time. It consists of the party traversing a video game board and completing certain objectives. The way to the physical challenge is usually blocked off until these objectives are complete.
In The Legend of Tenna, Kris, Susie, and Ralsei control video game versions of themselves while Tenna spectates and provides commentary.
Cooking Show is the physical challenge that follows the Desert Board. It consists of Kris serving food to hungry customers while dodging fire. The game ends in a loss if the popularity meter is fully depleted, and the game ends in a win if Kris survives until the time runs out or fills the popularity meter to its maximum limit.
The minigame can be replayed in the Green Room's arcade room in between rounds 1 and 2 of TV Time.
Rock Video is the physical challenge that follows the Island Board. It consists of Kris playing guitar and matching the rhythm as it appears on screen. The game ends in a loss if the popularity lights go out, and the game ends in a win once the song cover finishes.
The minigame can be replayed in the Green Room's arcade room in between Round 2 of TV Time. It can also be replayed in Chapter 4's TV Studio, with two new song covers added.
Monster Movie is a physical challenge that occurs outside of the main TV Time show. It can be played in the Green Room's arcade in between rounds 1 and 2 of TV Time.
The minigame consists of Susie protecting a Tenna statue from the many enemies throughout the room. The game ends in a loss if the statue is destroyed before defeating the "Spamcannon" enemy. The game ends in a win once the "Spamcannon" enemy is defeated, though the game continues indefinitely until 800 points have been rewarded.
The Ball Machine allows the party to insert POINTs for the potential to gain prizes. Inserting 1225 POINTs allows access to gacharoom_unknown.
The cowboy minigame is played twice in the greater TV World. It consists of Kris and Susie riding Ralsei and shooting the Shadowguys that appear from the train windows.
The Original Game is accessed from the Green Room's backstage area. To progress the Sword Route, the game must be played after each round of TV Time. It consists of a video game session similar to those from The Legend of Tenna and eventually culminates into a battle against the Shadow Mantle holder for the Shadow Mantle.
These minigames were introduced in Chapter 4.

A collection of Mike minigames are available after defeating the impostor Mikes in the TV Studio. Each minigame is hosted by a different Mike, and the games can be selected by inserting the Mikes into the Mike slot. There are three minigames in each version of the game, though the minigames are different on the Nintendo Switch 2 version.
All the minigames have high scores, with some having a lives system. How the lives are lost depends on the minigame, but all of them are lost if the lives are used up.

After completing each minigame, the Mikes will have special dialogue that differs depending on which minigame the player earned the highest score in. If the player wishes to reset their scores, they can do so by interacting with a "MichaelBomb" in the bottom-right corner of the room.
Colored trophies can be earned in each individual PC minigame by acquiring certain scores. These trophies will be displayed to the right of the "HISCORE" text on the TV screen in the minigame room.
Battat is a minigame hosted by Small Mike on PC, PlayStation, and Nintendo Switch. It consists of avoiding obstacles and collecting cats for score. It requires the device's mouse and microphone to play.
Jongler is a minigame hosted by Cowboy Hat Mike on PC, PlayStation, and Nintendo Switch. It consists of throwing cats into a hoop for score. It requires the device's mouse and microphone to play.
Pluey is a minigame hosted by Small Mike on Nintendo Switch 2 and Cat Mike on all other platforms. It consists of placing cats into a basket while avoiding raindrops. It requires the device's mouse to play.
Air Waves is a minigame hosted by Cowboy Hat Mike on Nintendo Switch 2. It consists of blocking projectiles using the shields controlled by the Joy-Con 2.
Main Performance is a minigame hosted by Cat Mike on Nintendo Switch 2. It consists of matching the given poses using the hands controlled by the Joy-Con 2.