Yep they are pulling out all of the stops with these levels I died a few times here so yeah pretty tough but I think this is like the semi final area so it's to be expected.
I also managed to fully upgrade the suit and find all of the sunken scroll.
The hammer power up is very fun but a little hard to control though.
As for the boss every time you hit him he splits up into more manta rays which each use different sub weapons on you so keep moving and shooting until you hit the real one.
PS:Next time we find out what this co called treasure is maybe finally get to gramps I feel that the next part might be the finale but don't hold me to that though LOL!