Design is definitely cubish, but somewhat interesting and original.
The map seems to be playable but very unbalanced. Also, I don't like this strange inclination to make door opening by shoot (if this is not a secret door).

Hellbase on The Quake Grave

The map is definitely interestingly designed and it's a good map for a first release. I really liked the part where you had to jump from the platform down into the water area surrounded by lava, because it's something a little different.

However, I think xDDGx got it right above, this map is completely imbalanced. It's perfectly paced and balanced up to the last 2 rooms where the map definitely earns its title. In the last room there are like 5-6 Shamblers running around a maze type setup.

I think the goal here was to create a map where you could grab the pent or the quad and go and destroy a room full of baddies. However, the items (pent and quad)are placed in such a way that they would run out in the middle of the very important fight by the exit so you may be left surrounded in a fight you can't win.

This map has very basic, cubed rooms as many early levels tend to, though there are a few spots of interesting architecture. The last few rooms are an onslaught of big nasty dudes, but thanks to the ridiculously easy-to-find secret power-ups and plentiful ammo, I didn't really have many problems.

Essentially a Doom level made in Quake. Not terrible, but crude and flat, and unbalanced as the previous comments mention. The author went on to do much better things.