Isle of Arrows gives new life to the tower defense genre. Not only are you placing your usual defense towers, but you will be building out the lane enemies travel down. This makes the gameplay never dull and always exciting as no 2 playthroughs are ever the same. The game features 3 different game modes as well, ranging from a traditional campaign to an endless gauntlet. Your objective is to build out the land and protect your core from enemies each wave. Each round you will draw a card that can either be a defensive tower, a path to extend the lane, or a special building/tile to place.
The main currency at your disposal is coins. These will let you skip drawn cards that are useless to your current situation. The coins can also be used to buy cards from the black market which can occasionally pop up. Aside from the pathing and defensive structures, you will also be given special buildings to place. These buildings can give you bonus coins or give other bonuses when their conditions are met. One example is a building that needs to be placed next to water, when done so this will give you 2 bonus coins.
By far the most challenging part is when you run out of land to build on. In order to have new land generated you will need to connect tiles with flags on them next to your already existing lane. The game does give you a little help by giving you special resources that can help you build off the map. The bridge material will let you place a building or path in a spot that doesn't have land. These are very rare though and need to be used with much care.
The enemies you face are plentiful and unique. The basic enemy's move at a normal speed and have low health. Then there are enemies that move fast and require a freeze bomb tile to slow them down. The most annoying though is the heavy shielded enemies. It will take many shots from your defense to break their armor before they take damage.
This is by far the most strategic tower defense game I have ever seen. The problem is it can be too difficult at times and can lead to frustration. This isn't a relaxing game that you can play mindlessly. You really have to think about every move you make and think ahead. The best game I can compare its strategic level to is chess.