There is absolutely no crypto mining going on whatsoever, you are just insane, delusional and/or paranoid.
That's clearly just hyperbole. But they still have a point. Whenever I open up `htop` running this and another Unity game, I see veadotube with 2 CPU intensive threads (it opens more but they appear to be low usage) at >100% CPU core usage (100-130, goes higher than 100 because of boost clocks I assume), while this other game (Riichi City) has only one CPU intensive thread at ~30-40% CPU core usage. Not that I know exactly how this app is written, since it's not open source, but it does smell like there are some loose ends somewhere.
$ /usr/bin/time ./veadotube\ mini.x86_64
^C211.53user 490.08system 9:53.59elapsed 118%CPU (0avgtext+0avgdata 510572maxresident)k 0inputs+18664outputs (3major+50440minor)pagefaults 0swaps
Honestly for a ~10 minute run the above is quite a bit.