Tips for level 13: the only cells that can attack the giant cell are the ones at the very top and very bottom. capture the back 3 cells quickly (do this by cutting tentacles) and use them to transfer energy to the top and bottom ones. your cell furthest back should have tentacles connected to the Southeast and Northwest cells, and these should be connected to North and South cells. The longer you hang on, the more your cells will grow and eventually taking out the giant enemy cell will be a breeze.
Tips for level 10: 1. you have more units then they do. utilize them! 2. My basic strategy was to try to attack their units while still keeping pressure on the neutral cell to make sure that they didn't get it. the ANT cell is a game changer, but remember your primary goal is to eliminate THEIR units. also, you have to send power to your other cells
 "Achievement Unlocked"){kind=icon}
 "Hungry Shapes"){kind=icon}
 "Pandemic 2"){kind=icon}
 "Pandemic"){kind=icon}
 "Tentacle Wars"){kind=icon}
 "Love"){kind=icon}