In BlueBerry your job is to shoot enemy bubbles with your weapon called jam. Which does a variety of different things depending on the enemy it's used to attack. There's a significant amount of strategy involved to make it through all the levels successfully. Make sure you don't forget to use your JAM on each enemy. It can have some extremely beneficial results. Jam fires bullets back at the enemy so you need to place it wisely. Use the ARROW KEYS to move, use "A" and "D" KEYS for Alternate Bubble Fire, use "S" KEY to Drop Jam (Use it to fire enemy weapons back at them) and "W" KEY to Fire Bubble (Either DuraBubble or GlideBubble).