first of all Gate is not easy or difficult from any of the engineering fiwld view. I had given the gate exam and i was studying electrical engineering.  

The gate exam is conducted by different iit every year. 

Yes, i know that there is different gte papers for different engineering field.

It also include reasoning questions, mathematical question as well as the question from your particular engineerin field

It is of 100 mark exam

1 mark mcq question-1/3 negative marking

2 mark mcq question -2/3 negative marking

Non mcq question-no negative marking

This all rules are same for all engineering gate exam .

So dont worry just prepare your gate exam with your engineering knowledge and reasoning abilities 

Well saying it easy for any steam doesn't make any sense. For a student from computer science he/she might be seeing the exam of mechanical difficult and same can be same for mechanical toward CSE. For the students studying their particular stream, it is easy for them and difficult for all the other. So it's not like exam is difficult for one steam and easy for other, it's just the preparation you have done to take on the exam. Without preparation even the simple exam might looks tough.