Mind that there will be a very slight amount of coupling between side-by-side traces (very little, with the ground plane filling in the gaps, but it might be discernible on a faster scope?), and the bends have a lower impedance on account of the way the fields distribute across the width of a curve (the velocity is effectively faster on the inside corner), which also contributes some dispersion (falling edge 'drool'). Being in FR-4, it'll also be fairly "drool-y" due to the dielectric properties. Which you can't really do much about, aside from perhaps an R+L (or a more complex network of some sort) at the termination.
Speaking of networks, I suppose the rise/fall time could be very slightly improved (no more than ~2x in the limit) by adding a small C or R+C in parallel with one or more of the output attenuator (series) resistors. That might be worth trying, I mean, if you had a scope to play with of course. (Nothing you'd bother with on the initial layout -- the extra pads would do as much to screw with the response as you'd be trying to fix. But it's something that can be tried by stacking chip components, a perfectly cromulent prototyping approach.)
So, for what it is, it's fine, and unless you have over 1GHz of scope bandwidth to hand, you probably won't be able to tell the artifacts in the first place!
Tim