I've found myself oddly drawn to Straftat in recent months.
For starters, it actually seems to be one of the few actually active Arena Shooters out there that has a quick and easy 'jump into a few rounds of deathmatch' energy about it. (as I've complained in the past, it's near-impossible to find a deathmatch shooter these days that isnt CoD or Halo). I think it's the closest thing we can get at the moment to the experience of joining a random CS 1.6 server with random user made maps and shooting the shit for a while.
It has a fuck-ugly style that really grows on you with time. I mean look at this guy. I love him:
It has a chaotic difficulty to its gameplay which also grows on you with time.
It's amazing that it's free, with optional map and costume packs.
Good vibes. Good game. Check it out if you haven't!
