It's an overall very fun and well optimized game, albeit with a few buts.
The theme/general look and feel are spot on. Hordes of insects to mow down, robots varying in giantness from a house to a skyscraper and beyond, and an occasional copyright-safe Godzilla to punch in the face with a mech.
Varying environments: cities with destructible buildings, mountains, caves, but the maps are sometimes reused between different missions with a different spawn point. They are, however, quite spacious, so it isn't very noticeable.
The missions try their hardest to mix things up with the story/objectives, but there are a lot of them, so they do get a bit repetitive at a point. On one hand, it kind of works, but on the other there isn't quite enough enemy variety to support them.
There are a lot of different weapons to try out, especially at first when you're getting all the new loot, but a good chunk of them are either straight up useless or you just outgrow them, as there are different equipment levels the higher in difficulty you go. Still, there are use cases for weapons from every category, so it isn't that bad, and there is fun to be had in picking just the right loadout for a particular goal.
Speaking of difficulty: while it does allow to tailor your experience (pick between simple fun, a bit of strategy, or unbearable suffering), the balance is kind of whack. EASY and NORMAL aren't even difficulties, HARD seems like the intended experience (challenging enough but not extremely punishing), but then the jump to HARDEST is very abrupt and together with INFERNO they are seemingly for people who hate themselves with a passion. Some missions are easier then others, though, so you can get some loot on the higher diffs to make it easier on yourself.
For the first playthrough, I highly recommend starting on NORMAL, switching to HARD as soon as you can (i.e. when you get some weapon variety) and then just staying there until the end. That way you can just complete missions in order without pausing to grind for armor, and there are still missions you can complete on HARDEST along the way for some better weapons. This is what's been working for me so far and I'm almost done with the missions on Ranger.
Anyway, cool game more than worth its listed price, and is an absolute steal on sale.
