My local store is trying something a little different that they call 'Escalation'. They've run it with 4-6 players, but three might work.
Each player starts with a 25 point ship deployed the edge of a board (spaced out evenly). When that is destroyed, they move on to a 40pt ship, rolling a dice to see where to spawn. Finally, the use a 55pt ship. A single victory point is awarded for destroying any other ship. The points value of each ship destroyed is recorded in case of ties.