Challenge

"fight your way through opponents of increasing difficulty"

- In-game description

Challenge is a gamemode in Island Wars 2 and Island Wars 2 Xmas, very similar to Duel.

Rules
Unlike in other game modes, you cannot set any rules whatsoever: the difficulty will always be the same, the length will always be the same, and you'll always be fighting alone against the computer instead of a friend on the same computer. Most people would probably consider this to be the most boring game mode of them all, due to its longevity.

Gameplay
It is the same as in Duel, as it goes like this:

The gameplay of each day is split into three rounds:


 * Sunrise, where the left player controls a plane and the right player controls a cannon. The goal of the left player is to destroy all of the right player's palm trees. This round ends when either all of the right player's trees are shot down or when the left player's plane is destroyed.
 * Noon, where essentially everything is the same, but the roles are switched: this time, the left player controls a cannon and the right player controls a plane.
 * Sunset, where both players control planes, and their goal is to shoot down each other. This round ends whenever either of the planes is destroyed

In normal circumstances (without bonuses acquired and mutators applied) Both the plane and the cannon have a set blaster energy, which recharges over time. With full blaster energy, a cannon can fire 10 bullets, and a plane can drop 5 bullets or fire 8 blaster shots. In all three rounds, the plane's bomb and the cannon's bullet cancel each other out when they collide. The cannon's hitpoints, since the cannon itself is invincible apart from the bullets, basically correspond to the number of palm trees they have undestroyed, which stays at 10. The plane's hitpoints correspond to the number of bullet hits it can withstand, which is initially 5, but flying into the water destroys it no matter the HP left. Both HPs recharge between the corresponding rounds or days, although both the alive and dead palm trees remain on the island for the remainder of the day in the case of both players, even visible during Sunset, for the sake of decoration.

Now try to do all of this, but ten times instead of once.

Ending
As per usual, after the last day of the final challenge ends, the "cease fire" screen appears, after which the camera pans to the player's island, and then is given a rating, depending heavily on the settings they played against and the mutators used, with which they can enter the leaderboards.

Mutators
All mutators available in Duel will apply here as well, as the gameplay is functionally the exact same.