I've seen some topics around talking about grass, but I wanted to mainly give some feedback about landscape and I hope devs will take it better than in other cases ..
Right now the landscape/terrain doesn't look that interesting , I noticed it's mostly just 1 layer especially in the older levels.
Since You have 20 developers and some budget I take it that there is someone responsible for the art side of the game
I imagine performance plays a big role and it's propably best to avoid using more layers/texture samples that are not really needed, but it would be nice to either rework base materials or just put in some macro texture to break down the dull surface.
As visible above , the terrain materials are pretty dull together , cliff material isn't too good either.
About the grass it looks like they don't have proper vertex normals (will help with grass blending, won't stand out that much) and it's not just colour issue (just a guess). You can also make use of material instances for the grass colour with close to no performance impact and have them matching the terrain with more control.
My overall suggestion is , it would be nice to have terrain materials reworked , make use of PBR and power of material editor within UE4.
Give substance designer a try, it will allow you to make quick procedural PBR materials
Also good work and congratulations on making a working base game , I am really looking forward to updates.
I hope someone will read it.