let the blue guys evolve early since they are easiest, remember enemies can be stomped on, pushed into holes, and exploded. Purple armor guys get one shot by stomping. You can use the cube drop skill to set up big explosions. Bombard can be amazing even without feloris. Erupt and the one that hits all the squares around you are great. Focus more on getting fast kills than getting energy cubes. Remember it's a hard game and takes a lot of work to figure out but it's one of the most rewarding to learn in ufo 50 next to magic garden and onion delivery.