It is probably the intended way, Spirit. The setup stands out too much.

It is a base/bunker map.

The map is less hordy than what i thought at first, the numbers are high but not close to hordes, and in combat you only see a few at once.

The brushes are quite big and the layout is simple but varied mainly linear. The choice of textures is good, except for the buttons as they don't stand out. This map has big influences from DM maps in brushwork, architecture and layout.

Combats are mainly straightforward with some different ones in the bunkers. They also get better with time. Ammo/health/ammo is a bit too much but still OK. Couldn't get to the secret so i can't say a thing about it.

For its time, it is quite nice.

This is really good: coherent, well put together, fun to smash through the large numbers of relatively weak opponents and just plain funny to double-shotgun dog after dog after dog. Obviously not an epic, but plain, honest fare done very well indeed.

I like this map; it does what it says on the Quake Tin. Plenty of carnage as you blitz through your foes, with plenty of opportunities for satisfying multikills with the GL as enemies fire at you out of their little bunkers. The layout is practical and well implemented for the most part, with a satisfying level of visual detail that gives the map a strong sense of quality and polish.

However... there are a few issues I had with the map. The armor at the start seems to be broken; if you pick it up and fight the enemies that pop out, you'll be stuck there with no way to continue the level. I get the feeling that the bars at the end of that area are supposed to lower at some point, but they never did for me and so I had to restart the map and play without the extra protection. Another is the jump past the "locked door". As Spirit highlighted, it doesn't feel like a movement trick is the proper way to progress in this level, but it seems to be the only way. It's difficult to fault the map for trying to be creative, but sometimes the player's hand needs to be better held if they are to be expected to know what to do.

Is it possible to end this map without rocket jump?

Yes, cosmaty: that's the slope jump that a couple of earlier commenters have mentioned.