Stupid boss one shoted me! But I was delightfully surprised to see the level was all new, and had a blast running through it again. I tried to cheese it and not kill anyone or pick up anything prior to the boss so I could fight with my projectile weapon, but it forced me into the sledgehammer. I like the idea, but the execution and control for it was frustrating at time. As somebody mentioned below, some knockback on the hammer would not only feel great, but it would give you a little space from the enemy, so you don't feel doomed to take damage.
Overall, this was a great entry and your team should be proud. I knew when I saw monkeys in the thumbnail I had to play it! Us ape gamers have got to stick together!
Good work.