A good way to beat level 45:
First spread out your Jellies so you have all the neutral Barracks. Then send all your Jellies to the top middle Fort. Once you have that take his top Lab and upgrade it all the way. Keep sending all your Jellies to this lab. Then use the capture power to take the fort to the left of the big red guy. (It doesn’t work on the big guy.) Wait until the big guy sends out a bunch of jellies then use all the Jellies you gained from taking the Fort and the ones in your Lab to attack him. Keep sending your jellies to your Lab and then attacking the big guy until you have him. Take the Forts and Labs next to the big guy and keep sending the Jellies you get from him to the middle Lab. (His Jellies move slow and the Jellies from Labs move faster.) Then just attack and finish off the last of the Reds.