This is the fourth NAB map made by Adam, and it is good to see that it is substantially more ambitious than the previous three: CrossBeam, Empty and Doublesided. They were really just beginner exercises; while this is still a tiny download (31KB when zipped - 200KB unzipped), it has a nice use of the Sequoia textures, it has water, and it has four rooms, this main area and three side-rooms, one of which you need a megajump to enter and leave.
So, it is a good step along the way, and a nice, playable map. Now that Adam has mastered water, I think next on his list ought to be making skyboxes, which look a lot better than just having a static cloud-textured ceiling - and then movers are always useful.
It is difficult to criticise an arena like this, which does what it sets out to do nicely. It has all the weapons, and pick-ups; I think I would avoid having those three floating 250-point lozenges, they are not a good habit to get into, and can make maps seem "laggy". Some ammunition would be useful, as well as the weapons themselves. Perhaps a bit more space would be good? The water areas in particular seem very cramped and narrow, and there is no real reason for that, with mapmaking you can have as much space as you like...
Anyway, it all works nicely, so check it out for yourself!