Tap the screen and smash those nasty bugs. Each touch will decease the critters life with a certain amount depending on the unit's type and active bonus. Pick up the gifts and gain the upper-hand on the invaders. The bonus given will increase with the wave level but be warned... not every gift is a blessing! For most positive bonuses there is a negative counter part. Devise you own strategy and counteract those negative effects to reach you're goal and fulfil you're destiny.
Reach wave 14 and you'll unlock the survival mode. How long can you're fight last in an completely random chain of events?