Break Monsieur John-Aeriks' encryption methods with a great deal of effort, and allow full power to flow into the railgun again.
{4} - Everything is really broken, but with a massive investment of manpower and your own genius, a partial fix is made.
Partial Power: +1 to cannon's raw power output
I Design and Buld a Time Dispersal gun which will Slow them down, giving us more time to work in the long run.
{4} - It looks horrible, and you're not quite sure how it works, but it
does work. It has a limited rate of fire, but it should be enough to get all or most of the bigger ships out of the way for a turn.
Instruct my workers to build a number of smaller turrets around the main one.
{1} - You try, but it turns out that all those people in super-factories have completely tapped out Europe's logistical throughput. Most commercial goods aren't even available anymore.
Shoot the cannon don't let these Xenos get first blood
{2}+2 vs {?} accuracy. {2}+1 vs {?} damage - A large volley of shots is fired. Amateur astronomers are unable to give an accurate damage estimate of completely unknown forces.
Build a factory producing tank drones to support the swarm with heavier firepower and the ability to tank hits
{4} - A factory for larger drones is built in Australia. It comes only shortly before the aliens arrive, and only an irrelevant few are built.
Deploy laser satellites in space! These satellites can be used to burn up incoming fire, or attack ships directly!
{4} - Laser sat defense net deployed.
Event!
Detection:
{1}
The laser satellites near the poles suddenly begin automated defensive fire.
{3}-1(surprise) vs {3} accuracy. {3}-1(surprise)-1(glancing blow) vs {2} damage.
Asteroids! The aliens must have redirected them towards the Earth, from an angle. The satellites shatter them, sending large fragments down across the planet.
{1}(survival) - The attack does massive damage to the biosphere, and the surface of the planet is rendered virtually uninhabitable. A few pockets of humanity survive underground.
{4}+3 vs {2} - The gun, safely entrenched in its super-bunker, remains fully functional.
Time slowing gun fires!
{6} vs {3} - All of the large alien vessels are nearly frozen in time, leaving the strike craft and escorts without support. A Hazen Field forms near Earth; further temporal effects will be completely unpredictable for years to come.
Gun Fires!
{1} vs {2} Accuracy. {6}-1+1 {vs} {2} damage.
In a frightening display, the gun covers the sky in a vast quantity of explosives. All smaller ships are destroyed before they reach orbit.
Humanity is nearly extinct.
Earth's atmosphere now has a high radioactive dust content.
The amateur astronomers previously relaying basic intel are unable to continue helping.
You are now in secret bunkers with minimal help or resources.
The gun still has a frightening amount of ammo. (Manually firing it again won't help.)
Most of the drones are still usable, but all the dust in the atmosphere is making command and control highly difficult.
The laser satellite grid is fine.
The unsupported larger alien ships are quickly unfreezing, and will arrive in another turn.