Good Map with A disaster finale

First 3 Chapters are interesting but full of deadly traps, middle 3 Chapters seems a little too short, and the final chapter is a disaster.
The final chapter is too long, first part and the second part could be sprerated into 2 Chapter, It's exhausting to encounter a resuce event in a very large area full of tank from everywhere and endless horde after a exciting escape from a laboratory.
Also, the final chapter is full of bugs. Hint info is not working very well during this whole map, and in the final chapter, after taking care of several hordes , you will find no normal enemy occurs in the recure area, because all of them respawns in a room with the door permenently blocked. It's a very frustrating finale for such a good map.