As far as I know, there's no real "in depth" reviews out there.
You may find Youtube videos etc, but they're not (all) going to speak to the 1% and .1% like more professional reviews commonly do these days, they'll speak more to min/ave.
Remember, the G5400 is only available as of Q2, so hasn't been out that long at all, and hardly the priority chip to test among most reviewers.
*EDIT* Found this:
https://www.youtube.com/watch?v=SRHKFyvpnSA
Of course, take Youtube "benchmarks" with a somewhere between a pinch and a ton of salt.... but gives you some idea.
tl;dr it struggles a lot of the time. Still a mostly playable experience from what I caught from a brief skim through..... but for $70ish, it doesn't seem like a great choice.