BATTLE BEYOND SPACE
In 45-60 minutes. And 9 turns. In an asteroid field.
The combat system is diceless and extremely deadly. On a turn, you choose one of your three squadrons, move and fire with it, then get to move one of your two capital ships.
The big difference between the players is the super-secret alien power of technology which they can spring on another player at any time. Some are one-use, amazingly powerful items (aka Death Blossom), some are more subtle, long-term effects.