It's seemingly an "open world", but it's not open at all. You need to loot certain items from certain places to get that upgrade, so you can advance to next area. Also, it lacks the "base building" and "sandbox" features nearly completely – at least I could find them. Picking up has weird delay, you need to run back and forth to pick up. On the plus side, it's very good and polished in its own area: smash & collect tube runner. Combat is all about tactic.