The idea is very cool!
I really wanted to get further, but after few minutes of trying to get on one of the first "jumps" I just gave up. I tried to switch to the pistol after shotgun shot as you suggest, but it was still not enough.
I respect that hard games has its audience and its populat genre, unfortunatelly I am not patient enough, which makes it so hard to rate. For this reason I decided not to and leave it to someone who is skileld enough. I hope it is ok. :-)