It may just be my play style or my skill choices but I found that once you get multiple islands and stop spending nearly 100% of your time collecting resources they spawn too much and fill almost every space on the islands.
Could the spawning speed of resources be adjusted either manually or automatically depending on the number of resources on an island so you can still walk? As has been mentioned a few times paths would help a lot with this. Spawning speed might also be something to consider when multiple players are in a game.
The game is still great regardless.