That spiral power routing you have to resort to with 2-layers is a bit iffy. Even if you bypass it at every power pin, you'll create an interesting LCLCLC loop. I might be worrying for no reason, but I'm saying this because this layout looks very familiar; I made such a board with Cyclone III and gigabit ethernet phy somewhere around 2010 and I never got very far because I had obvious signal integrity issues and then lost interest in the project. I think I used a 240-pin package so it was larger than this and the ETH PHY had similar spiral power routing, but in any case, never again, just in case. Everything will be so much easier with more layers to work with, and proper grounding.
Although, even with 4 layers, you still need to get a bit creative with power distribution given three different voltage buses required.
Look at PCB prices at pcbshopper.com and decide how much worth your time (longer design with fewer layers) and signal integrity (inferior result with fewer layers) are.