Your terrain looks really cool and I'm going to make a note to change the terrain in Mars Lander from grey to something more red/brown. Terrain collision would be harder I guess but if someone thinks they can do it then there is no harm starting a branch on github and then abandoning it if it doesn't work.
In terms of random encounters - we can have weather phenomenon. Good idea. I think if we have a co-op/SP mode then rescuing civvies and each other might be fun. I'll put those ideas into github.
Buy all means help with the art. You clearly have some experience and you'll get credit of course. I actually like your lander and rocks and little man. So clear considering low resolution.
Thinking out loud, we have some buildings and gas tanks. We need a lander. Gunroar has proposed a left/right side-view but I don't think that will work. The lander will nearly always face up with the thruster/engine/flames facing down but I'll let GR think about that. I like the steam-punk feel the gas tank and his proposal has but that's just me.
Meteor storms? I actually thought when a ship crashes too hard (but is not destroyed) then a little man jumps out with a spanner and repairs it for x seconds before jumping in and taking off. This can be a sprite sheet with frames that can be animated. That might be fun.
Tornado's? Never thought of that. Not sure how that would work with the game.
Things to fly over. We have two buildings and I hope to make a 'cityscape' from those two buildings that appears randomly. That might be - idk - 150 pixels wide and shows a 'Mars city' that scoots by as you fly to the next base.
What about concept art? Doodles on a page that describe how something might look? The game has a rangefinder that is really just numbers? I don't know what a rangefinder should look like so maybe some suggestions?
We have 'gas tank bases' to land and get gas but what about a different type of base that you can land and get repairs? That would require a new graphic like a garage or a crane or something like that.
Don't forget that we can use sprite sheets to animate anything we want - like the landing lights and smoke puffs.
This link shows all the github cards that are tagged with 'graphics' (don't need a github account):
https://github.com/togfoxy/MarsLander/p ... 3Agraphics
You can see there are lots of ways to help.
