For me, HAWKEN has been the most fun I've ever had in a video game. It's fast-paced, it's challenging, and it's badass. Today, however, the game has its fair share of flaws. (Please note: I have not tried every mech out, and therefore I don't have comprehensive experience of weapons and mechs.)
The game is incredibly challenging. Often times, victory depends on both teamwork and on personal skill. Sticking with your teammates often results in victory.
HAWKEN offers a unique combat system, where your turn speed is locked at a certain level to make combat more interesting.
The default starter mech, the CR-T Recruit, is well-balanced and very powerful in the right hands.
Every* mech's special ability is very useful, and can be utilized in numerous situations. *Note that some mechs share the same ability (CR-T and the Assault mech).
All mechs have the ability to dodge left or right to avoid enemy fire. In addition, all mechs can fly for a short period of time.
Weapons feel well-rounded and powerful against most enemies.
The game offers Deathmatch, Team Deathmatch, Missile Assault, Siege, Co-op Team Deathmatch, and Co-op Bot Destruction. There's plenty of variation in the gamemodes, but the same basic concept rings true: shoot the other mechs.
Mech customization / cosmetics (note that cosmetics can only be bought with Meteor credits, which cost real money
Each map, in detail and in gameplay, feels very different. The amount of detail put into maps is also commendable.
The game doesn't feel as though you can pay your way to glory. At least, not for very cheap.
There's been a disturbing lack of new content in HAWKEN lately, and the reason for that (though the topic is hotly debated) is that the company (companies) that made HAWKEN have become unresponsive, and seem to be no longer servicing the game or its playerbase. Servers are still running, but developer forums and helpdesk have been shut down.
To gain enough HC (in-game, non-paid currency) to buy new mechs or parts for already-owned mechs, an intense amount of grinding is required. Despite the 250-HC bonus you can recieve (up to 6 times a day) for winning a match in any of the six gamemodes, there is still a lot of playtime required to buy the things you want.
The game doesn't really have a set storyline that's explained to players (...that I know of. feel free to correct me on this.). Looking for some kind of backstory on the nanovirus that has taken over the planet? Want to know more about Prosk or Sentium? You're outta luck.
Hacking is a notorious issue in HAWKEN, though I personally haven't found any hackers for certain in my time playing the game.
The playerbase is awfully small, with a little over 300 people playing at any given time. You'll start to recognize usernames pretty quickly.
Though HAWKEN has its glaring flaws, I've had plenty of fun playing it. I reccomend this game to anybody looking for something new.