Although Armageddon takes a different approach than Red Faction: Guerilla, being able to destroy just about anything in the environment is the heart of the game. Blow holes in walls, topple guard towers... you name it and you can probably break it (and, more impressively, rebuilt it). It is an incredibly cool feature; it adds a new level of fun and strategy to shootouts and even a slight sense of exploration. It is not the open-world surface of Mars, but the underground still looks pretty good.
Watching a tower fall is one thing, but the sound is what sells it. Structures bend, creak and whine as they crumble around you. It is well done and makes it hard to not want to leave a path of destruction in your wake. The downside to the symphony of destruction is background music is sometimes lost. Rest assured, it is still there and fills in the gaps nicely, piping in just when you want it to and setting the mood perfectly.
Voice-work is pitch perfect and noteworthy. You don't spend enough time with the characters during the campaign, but it's easy to get a feel for their personalities and relationships just by listening to their voices.