Not really. Its not much of an ARPG at all in the Diablo sense of it.
You do missions, various ones on various planets to get credits, resources and mods. Credits can be used to buy blue prints, blue prints use resources to make weapons/armours etc. You never pick up guns or armour from killing guys. The mods you get go into your suit or your weapons and improve them, but there’s a limited amount. For example, the shotgun has say 10 different mods, and 8 slots. You can combine mods of the same type to improve the effectiveness of it.
Different systems (places you go to do missions) will have different resources in them.
You can also buy weapons and blueprints directly with Platinum (the in game real money currency) and some weapons can be bought with credits (the in game fake money).
So any upgrades you get are from buying the blueprints or buying them outright instead of just getting a lucky drop.