Surviving Mars

The good news is you don't have to do this before Sol 100 so you can take your time battle through the tough early-mid game, then once you get towards the late game you should have plenty of resources (Build all the wonders!) to easily expand to 500 colonists.

To get 500% difficulty rating it takes into consideration:

* Your Faction: (Just choosing Russia puts you on 250% difficulty!)
* Your commander: Futurist is the most difficult which bumps you up to 310% but I went with Astrologist at 300% for them early deep scans. (Hydro engineer & Rocket Scientest are also 300%)
* Your mystery: Taking a hard mystery puts you on 360 difficulty. Marsgate is pretty easy, just make sure to research the tech straight away when it becomes available and build around 5 turrets at each side of your base to defend the attack.
Game Rules: I would reccomend Hunger (A farm a dome should be enough to keep the colonists fed) and Inflation (Won't hurt you early game and by late game you should be either self sufficient or profitable) These 2 rules take the difficulty up to 440% which is more than enough.
You could pick Long Ride instead of either of them but Russia already suffers from slower rockets so the choice is yours.
I actually went with Increased Production (Give me the resources!) offset by Rebel Yell along side Hunger & Inflation. Rebel Yell isn't that bad, I'd reccomend filtering all rebels into 1 dome. They might blow up the occasional building but at least they aren't upsetting anybody else!
This is up to you, you can have any 2 of the negative rules or 3 and the increased production.
*Map Selection: Depending on what rules you picked just find a landing spot that takes the difficulty up to at least 500%


Once you start playing don't expand too aggressively. The Russian unique vehicle (RC Driller) can dig in metal and rare metal resource spots so you can at least get access to them as you scan the map. Then use the transporter to bring these back to your colony to progress.
If you've been playing with preferable game rules in the past (100% difficulty) you'll notice things are a bit tougher. You'll get hit by more sand storms, cold spots etc. so make sure you have plenty of resources saved up although you'll nearly always spring leaks that lose these resources during these disasters so be prepared and just expand naturally.
When Marsgate attacks just make sure you have enough turrets to protect the parts of your base that they are likely to attack from. I found grouping 4-6 turrets at either end of my colony was enough to fend off both waves (Although I did lose all of my vehicles in the attack)
Once you get to the end game and can build wonders all of the difficulty is gone (Well frustration as it isn't that hard) and you can be more aggressive with your expansion to get the 500 colonists. I unlocked this around Sol 130.