I don't want to sound rude but have you been on the server, PSH? It's not an AIM Server but a MULTI-ARENA server. Let me explain the mod briefly. It's basically you joining the server and once you do join, you'll be assigned to a specific ARENA. I can't tell which one since it depends on the amount of the players on the server. For example, if there is six players playing then you'll will be assigned to ARENA 3 in which you'll 1v1 an opponent. Whoever wins that 1v1 (just a kill, it's all you need) gets to move up the "ladder" and then that person shall proceed (spawn) in ARENA 2 where he battles another opponent. The loser of that first 1v1 gets put down in the ladder and should be pushed to ARENA 4 but if it's six people on the server then he basically fights another opponent (most likely the loser of the ARENA 2 match-up). If there is an odd number of people then you've get put into an ARENA that is empty as you've got to wait for the loser of the ARENA above you to lose as the loser gets kicked into your ARENA and you get to move up.
The aim of this is pretty simple, your objective is to stay at the top as you'll get the hardest people.
This mod is brilliant and I think it will consume most of your time. Pim could probably open up a normal AIM server but he decided to go for an unorthodox kind of the mod and hopefully more people will like it as I think it's honestly a great server. Nevertheless, there will be an upcoming tournament and I strongly advise anyone who is willing to take part in it to start playing and pracc'ing hard for it! Both, this and FFA DM servers are great for such exercise. More information later!

Sorry for going a tad off-topic :/