Supernauts Mission Guide: San Francisco - Mission 4, King of the Hill
Objective: Rescue 1 Citizen, rescue all cit, get all coins
Reward: 10 Coins, 644SP
Grab the Zapper on the top of the hill, and then begin removing all the soil on the top of it. Under the southern part of the hill you'll find the Timber Zapper, and the mound near the rocket hides a Citizen.
Once freed, follow the Citizen as far as they'll go, and then build a bridge using Timber. Grab the nearby Coin, follow the Citizen again and build another bridge for them to reach the life boat.
Now go back to where the last Citizen is trapped behind glass, and build a bridge to the nearby hill, rescuing them. Again you should remove the soil there, as you'll find your nineth Coin, then simply walk over to the roof for Coin ten.