I love ANNO games since playing 1602 yeaaaaarss ago. 
Yes, we will still use portals, through which we could walk on surface. I described just the simple mechanism of screen transition between one and two world (like in ANNO 2070) - by using mouse scroll or I.e. Alt + arrows or I.e. F8 button (for those who don't like clicking like me :p)
or
by clicking the button (do you see it placed in the middle of compass? BTW + 1 for you) + arrows that could be placed around the compass.
The idea of unlocking possibility to transition only when you get first portal is great + 1. The same mechanism I saw in Civilization: Call to Power I when you built first space ship and you can enter the space zone above the earth and find wormhole and real aliens...
Guard Stations is great idea - + 1.
Yes, we will still use portals, through which we could walk on surface. I described just the simple mechanism of screen transition between one and two world (like in ANNO 2070) - by using mouse scroll or I.e. Alt + arrows or I.e. F8 button (for those who don't like clicking like me :p)
or
by clicking the button (do you see it placed in the middle of compass? BTW + 1 for you) + arrows that could be placed around the compass.
The idea of unlocking possibility to transition only when you get first portal is great + 1. The same mechanism I saw in Civilization: Call to Power I when you built first space ship and you can enter the space zone above the earth and find wormhole and real aliens...
Guard Stations is great idea - + 1.
Spec: Win 10, ATI 7800 HD, res: 1280x1024x75. I support The Venus Project & Resource-Based Economy