What's funny is that I'd have expected the lensing effect to be the part they'd have been hesitant to add, and instead opt for a black spherical shadow / event horizon (depending on how accurate they want to be) at the very least, possibly with a white hazy ring around it as a photon sphere. Those would be easy to represent, relatively speaking, and yet aren't included.
The accretion disc is a whole separate matter, and to make that work nicely with the lensing effect would be a little more difficult, though not impossible.
Black holes should be terrifying and beautiful.
(and I'm avoiding making comparisons with Space Engine, since that program is entirely about the visuals, without having to work in a game environment, so it's not a fair comparison).