This looks pretty good for a first mapping attempt by Braveheart. Once you unzip the download, you need to right-click on the map icon, choose "rename", and add a "PM-" to the start of the name, okay? Otherwise your computer won't know this is a pointblast map! You'd better not correct the spelling to "Armageddon" though, as thta would confuse everybody.
It's pretty dark where you spawn, but you should just be able to see the edge of one of the lava-coloured craters, so head that way. The small grey pit between them lets you fall into a big cavern, with plenty of weapons and pick-ups - unfortunately, the drop kills you, but on one of the miniature mountains there is a teleporter to take you down. The trip back is from a position right in the middle of the room, so it is rather easy to leave before you may want to...
I am not convinced that you could have much of a game here, and the exploration side is a bit limited. Still, Braveheart shows that he can make a distinctive, working map, and that means that things are likely to improve from here on in. He is working on a second beta, it will be interesting to see how it improves on this one.