I post lots of suggestion in the beta testing topic 
– a restart button while in game, so we don’t have to exit to the main menu for restarting. I love a perfect score, once the barriers screwed up, I need to restart the game.
– Commander/Hero selections with each hero have different abilities and upgradeable skills. This new updates can be implemented as DLC/IAP along with new maps.
– Multiple profile slots.
– Units, aliens and heroes database and info.
I remembered Sentinel 2 showing little aliens description while on main menu. Must be awesome to know what these aliens like to eat etc Something like a database or dictionary.
– ‘Angry Birds’ star style for clearing a stage with perfect barriers. Indicator.
– access Game Center while inside the game
– Tap to fast points calculation in the Battle Report (want to see, no skip by clicking back button 
)
– watch/replay intro button in settings (because the intro so cool )