Space battles
Try to be efficient during space battles. Rely on focus fire strategy that was demonstrated during the tutorial. To do this, tap the "Select All" button to select all your troops. Then, tap an enemy ship to have all of those ships fire on that target. If AI control is on, after that enemy ship is destroyed all your allied ships will automatically target the enemy that is closest to them. You will have to manually re-target to focus fire on another enemy ship. When one of your ships takes too much damage, pull them back and position an undamaged ship on the front line.