Before I forget, let's recap the additional stuffs introduced in the Metal Slug Defense V1.15.0 (updated weeks ago):
New Areas in the 5th Map
After the Hong Kong and Canada Northern, two more regions are added - Egypt and Iran. As usual, I still find them easy to beat :)
5 more missions added, 61st to 70th. Interestingly, Leona shows up twice out of 5 New Missions here. So don't overlook this special unit. It has been mentioned again and again. Activating her special skill at the critical timing is just super awesome.
One interesting thing to mention, in the Wi-Fi Versus mode, there is a shortcut button to choose your default game mode. With that, you can skip those tedious steps to join the game.
Last but not least, there is a big sale on the Medals (Up to 70% if not mistaken).