Kraken Island

Invasion
Be prepared to face waves of skeletons desperate to take possession of you. Defend your skin and beat all the scores!
This game mode offers an arcade-style shooting experience. The game adapts its difficulty throughout the game, right up to the climax, for a gripping experience! 

Treasure Hunt
Have you found the Captain's treasure? His damned crew will do anything to get it back. Don't turn your attention away from the chest!
This game mode lets players defend their treasure from the waves of skeletons that want to take it away. The difficulty increases throughout the game, right up to the climax! You'll need to stay close to the chest to collect as much gold as possible.

Infinite
The waves of enemies just won't stop? Even better, you'll get more points!
This game offers difficulty level that increases only slightly.

Infinite Treasure
It looks like this treasure is huge - we've hit the jackpot! But the squelches are really mad! 
This game mode is the equivalent of Treasure Hunt, with a constant level of difficulty.