The Earth Defense Force series has never been particularly good, especially if you look at it from a purely objective standpoint. The graphics are often muddy, the voice acting is so terrible its hilarious, the entire plot is b-movie cheese, and the action is completely and utterly over the top. However, the EDF games do have one very important advantage working in their favor, they're pretty damn fun!
Earth Defense Force 2025, or The Shadow of New Despair as its known nowadays, is a perfect example of this as it look quite dreadful on the screenshots, but is actually a whole lot of fun according to the majority of Steam reviews. Here's the trailer to give you an idea of just how cheesy the EDF series really is:
Shadow of the New Despair brings with it four different classes with 800 weapons at their disposal and 80 missions to use those weapons against the most overwhelmingly numerous Ravager force the series has seen so far. While there is a singleplayer mode available, my advice is to play EDF in co-op multiplayer as this sort of game thrives on shared experiences. Chainsaw-ing through an entire horde of alien ants just isn't the same without someone to fist-bump right afterwards.
If you're interested in some mindless, explosion-fueled action you can grab Earth Defense Force 4.1 - Shadow of the New Despair on Steam at a €32 price tag, which includes the currently ongoing 30% discount.