A twist on the classic Tower Defense genre.

You play guiding the migratory species of "Colins" (a name derived from the taxonomical subfamily of the lemming, of course!) on their migration path. However, along the way, you encounter towers that are dead-set on stopping your migration! You have to spawn Colins to complete each step of the migration. On each level, you have a limited amount of food (in the form of delicious tree bark) that you can use to spawn in more Colins. Different Colins have different health and speed, cost different amounts of bark, and come with other unique abilities. Figure out which combination of Colins is best for each level to pass all ten! Will you be able to complete the migration and reach Colin utopia, the Arvicoliny?