Beaches everywhere! Mountains and patches of water break up the large land mass, and not everyone has easy access to water. The top corner players have a slight defensive advantage against tank rushes, but are fully exposed to naval and air strikes.
Top-left has very limited ore supply, so capturing the derricks on the peninsula (or islands a tad further) will be the key to keeping up. Bottom-left will have trouble with congestion, but has a decent sized stash of ore no one else will be able to reach. Top-right might be the most challenging spot, although has it's own peninsula to position anti-air units to help with defense early on, and can exert some defensive pressure surrounding the cove below.
Lots of derricks, 2 machine shops (left-middle, right-middle), 1 airport (top island)...
http://aproposer.net/ra2/newworld_YR.zip
