Try and collect all of the lemon babies as you go through the levels. Each level will have a different goal it wants you to reach but it doesn't tell you until the end. Strive for perfection and redo the level if you have not achieved the goal completely. Kill all of your enemies as you travel through the level and be sure to free and collect all of the lemon babies. You will complete the level by reaching the exit that is at the end. Watch out for collapsing trails, rats, and deadly green goo. This is a very fun and addicting game.