Hi,
Walking/ground distance traveled milestones currently are quite bad and I think should be somehow changed and/or removed. They are very tedious and not fun.
Walking - first of all walking up to 100km is pretty ridiculous on it's own. 2nd - it can be pretty frustrating to walk on the planets with very low gravity so that I don't think anyone will bother to walk more than a few hundred meters in such conditions. 3rd - in some places (Sergeaa in particular) droods start melting in matter of seconds making it pretty much impossible to walk more than a few meters.
Grounded distance traveled - similar problems. Distances are way too long, up to 1000km. Taking optimistic scenario that you can drive at a constant 40km/h speed that is 25h of driving. On T.T. 1000km would probably mean you need to circle it several times, with almost no gravity present too. Heat can also be a problem, on Sergeaa wheels melt. It's possible to shield them to some degree, but without any radiator parts and the way heat works at the moment - any solution that I can figure out in the end relies on you constantly stopping for your wheels to cool down.
So I would suggest that these milestones would be redesigned somehow.
Some ideas:
* distances could be reduced to more reasonable;
* these milestones could be removed from some of the planets where the environment is unsuitable;
* instead of walked distance there could be milestones for number of droods that visited the planet (multiple droods could be brought in a single ship making this challenging but not necessarily tedious; incentive to use droods which currently are very underutilized in career mode; environment doesn't matter as much because droods don't necessarily need to step out of the spacecraft);
* as an extension to the above new milestone could be another milestone - number of droods brought back to Droo after landing on other planets. Again - challenging, but not in a tedious way.