Earth Defense Force 6. It's great - wave after wave of mysterious monsters (ants, wasps, spiders), basically humans (frog-people), and hideous non-humans (greys), now with more robots and terrifying demon gods.

But it's one to play after playing Earth Defense Force 5, because it does have an actual plot - well, a mashup of monster b-movie tropes that somehow manages to be impressively grim and cheerfully absurd. It's just that it mostly assumes you've played EDF5 as it only cherry picks a few notable line. A lot of levels are some of the better levels of EDF5 with a twist, and since the game itself isn't a dramatic upgrade in mechanics (though there are a lot of little improvements) it's not worth skipping 5.

It does need more Crazy Space Laser ~~Lady~~ GOD though. She's the best.