If you put enough power into it anything will fly. Will it fly well? That depends on how you define "well".

Flat wings usually have higher drag as they tend to stall or suffer from separation bubbles at much lower angles of attack. So it'll glide like a duck full of buckshot unless it is VERY light. And making a wing out of ply goes against that idea. And if you wish to do maneuvers with it then it'll fly terrible compared to even half decent airfoils based on my experience with flat airfoils.

Unless it's light and has lots of power then the prop blast will just push it everywhere. Pizza box fliers with their flat wings and strong engines do fine but when they go to low throttle they look like they glide like a sack of hammers from the videos that I've seen and from what I've read about how they fly.