This is a shooting defense game mixed with a little bit of time management. The story goes that the planet suffered nuclear catastrophe and the animals were mutated into to vicious monsters. You are a scientist survivor and you have what could very well be the last savior for this planet: a plant. You need to manage your time between shooting down monsters that try to eat you for food, research for upgrades and growing the plant. The best tip I can give you going into this game is that you can jump over the ground monsters. Having that ability makes this game far better than it would have been without it.