The very first thing you should do is bridge close to the cracked bridge to the left of your island and build a generator next to it. By salvaging the Generator you can destroy the Bridge . You must do this twice before the bridge will collapse. Proceed to connecting to the geyser in the gap and send all your bulfs to collect from it.
Once they're mining connect to a few more geysers and keep an eye on your Sun Workshop and island waiting for the computer's attack. Besides your island, your opponent will attack your bulfs who are collecting. Build sun barricades to protect your bulfs from the cannons the computer builds. Just remember to build lots of sun barricades.
While you are bridging further towards the opponent and geysers (bridge on both sides of your isle) build lots of sun bars so that you can connect them across your island for better protection.
Once you take their priest with a transport they will start building again and quicker. The computer will build lots of thunder and ice cannons but they can't do much if you have good sun barracades built. Just get the Golem to your Altar , Sacrifice him, and win.