Until you launch rocket, all is well and no changes here.
Once you launch rocket you trigger attack on your silo, that will be provided by your LOVELY alien queen.
Flying (possibly? could be regular spitter) spitting monster with (10k easy -20k medium -50k hard-100k freedom bringer)*number of launches HP.
Attack damage +5% with every rocket. Range should be on par with gun turret.
Too bored of just defending?
You launch rocket again you get
Big alien hive that spawns frenzied biters that have 10k+(50*number of spawns*number of launches) biters every second and send them to attack your base. So you wont always get attacking alien but you get random hive within reasonable distance hidden sending biters. 1st big alien hive would work like this: 10050 hp biter attack and 1 second later 10100hp 1 second later 10150hp biters so you'll forced to rush and kill it fast or you might end up with 1 000 000hp biters to deal with.
If you launch few more rockets it would get to 10100 -> 10200 -> 10300 so with every 2nd rocket you'd get harder enemies to deal with.
So do you spend your research on more damage or more mining? Stuff will get harder soon!
Every 10th rocket you get boss fight!
100k-200k-500k-1000k (difficulty settings) hp biter spawned somewhere, he's no threat right? He just stands there and do nothing no problem right? Wrong! Every HERO biter present on map doubles damage of all biters!
UNFAIR! Maybe but here's some candy!
Every 25th rocket will spawn much needed space science pack field (crashed ship) worth 20 launches! But biters like to eat them too so you race there fortify it and mine it while all biters want to take a bite out of it! Don't ignore it or they will mine it for you. Such a waste of space tech.
100th wave will spawn golden hive that explodes after 5min if you don't find it (all biters +400% HP +200% dmg +100% help radius while it last) will you try to hold your line or kill it for sweet sweet HP/DMG boost to your guns/turrets/ammo?
TLDR -
Every n rocket launch - flying boss
every 2n rocket launch dangerous hive
every 10th launch hero biter that boost other biters
every 25th launch crashed ship with extra science that biters try to steal first
every 100th launch biters go berserk while golden hive is alive (self destruct hive after 5 min)
