Complete lack of anything produced by games workshop assets wise, and 0 money changing hands. If they want to take issue with it, fine, I actually contacted them about making an official version and they never got back to me, so they may reconsider that offer if there is a working game out there that is attracting players.
For those who seem to disbelieve that this is happening, i say again , this is 1 WEEK of work. I started last Tuesday and I already have all of this together. It's going to happen unless games workshop take issue with it again, which is unlikely to happen quickly.
Urgh ok let's briefly retread this one again.
You won't get into any trouble if you don't use GW assets and lore directly - they can't trademark big burly men shooting their way through space, or space orcs, or space elves -
you can't trademark an idea. Halo/Gears of War are all Space marines and they're fine.
What they can do is send you a cease and desist (at most to start with, no immediate suing) if you use a direct likeness to their assets - it doesn't matter if they didn't create them or whatever, if they look exactly like their version of a space marine/eldar/etc. or use the same names and 'lore' then they own it. No wiggle room.
The issue is your space marines do look *exactly* like theirs - that's going to be a problem if this goes remotely well, and it'll be doubled if you use all the same race names etc. What I've been trying to tell every new creator is that they need to do something more generic. Either creating a base game which is very opening to modding is one way (even just having all the names in text files would be fine), or create your own lore and fiction which has the same theme but doesn't use the same names/assets. If you do this, you will be
FINE.
Alternatively let it slide and take your chances, but don't think that 0 money changing hands makes a difference (you using their trademarks potentially takes sales away from legit GW games which their lawyers will be able to argue into the £10000s) and GW have shown they don't care about stuff being just a hobby etc. At some point if it does well, they will come after you.