Jeez, been a long time since I looked at those rules!
IIRC, they were stepped up a notch from Battletech/Aerotech on the damage scale, but were otherwise pretty similar to Aerotech (if you've played AT). A lot of family similarities to Battletech, gotta manage heat, etc.
So, not bad rules for ginormous spaceships. A bit record-keeping intensive, though.
From what I remember, Aerotech fighters couldn't really do a whole lot of damage to a WarShip. You needed either a whole lot of mech-scale guns or some actual naval-caliber pieces, as one Battlespace damage point was 10 Battletech damage points. Again, IIRC. This meant that you can't do much Gundam- or Macross-style ship-carving, but you could build and send heavily-armed 'Dropships' in to blow the hell out of the opponent's warships.
Had some fascinating ideas regarding a limited jump-based FTL system, like how if you had enough computer horsepower to predict where all the planets were you could jump in very close to a planet (at LaGrange points), but there was a great risk of disappearing entirely if your computers messed up, or you could jump in at a point well away from the ecliptic (plane of planet's orbits) which was much safer in terms of misjump chance.
I think what killed the game for me was a mix of lack of opponents and record keeping. I was not much of a fan of record keeping when I was 12 or thereabouts!
looks for scenario material in a World War IV boardgame.