Swarm Arena is a great concept for a simple 1-on-1 battle arena game that is rather unique. You control a swarm of flying pixel thingies that when in range of your ship can be used defensively or offensively. Defense, forces the swarm to hold its position, providing you with some cover against incoming attacks, where Offensive has a number of modes (shoot, circle) used to push your swarm out to attack your opponent. The first person to hit the other ship wins.
The biggest issue I have is the lack of control you feel over your swarm. Despite any tactics you may try, such as seeing an opening to quickly attack your foe, your swarm doesn't move in to attack as you may expect making your chance to hit seem very random. Wrongly timed attacks can result in almost instant loss of your entire swarm leaving you very frustrated and likely to loose the round.
There are only a few different game modes to play, and with the age of this title now there is no-one playing online anymore. Unless you have friends who want to play you are stuck with the AI or score challenge modes. Talking AI, this has to be a strong point of the game. AI is tough (very tough!) and smart which is rare to find in a Triple-A title let alone a small indie game, but again due to the poor control system over your swarm this ultimately turns to frustration and not a legitimate challenge. This had great potential but simply doesn't pull it off!
keep you entertained for an hour or two, but would be unlikely to get much more out of it. I would only recommend grabbing this if you find it on a 75-90% off sale.