See that is my problem with whole Highlander premise. "The Game" Any reboot should reject it completely. Just have it be about a war among immortals. Some exist in allied factions. Some try to sit it out and not get involved but are drawn in against their wishes. Others are lone wolves out for themselves. Cut out the mystical mumbo jumbo and it would be simpler and appeal to more people.
That's the exact premise of the TV series. There WAS supposed to be a Gathering happening, and in the first season they went so far as to state explicitly that it was going on at the time. Thing is, they didn't really show any evidence that anything was happening, save for the occasional implication that the Gathering was compelling immortals to meet and fight (but not "gather" anywhere). As the series continued, the producers realized that making the Gathering a running plot point was limiting, so they quietly removed it from the show and never really referred to it as part of the Game.
My feeling is that immortality in Highlander is simply there, and there is no "Game". It may have been invented or evolved, along with various other rules, thousands of years ago as a way for the early Immortal culture to come to grips with living forever and assorted decapitations. The series shows NO evidence that doing anything on holy ground would be catastrophic (they only suggest it MIGHT); that there is any actual Prize or what would happen; and until Endgame there was no real implication that killing lots of Immortals would eventually make you more powerful (fans tend to think that it's the other way around - you're powerful / skilled in the first place, and as a result you kill more Immortals, re: Connor, Duncan, Brian Cullen et. al.).
I like Highlander as a universe when there isn't an end to it - the entertainment comes from examining immortality and what it means / does to the people who have or can live for centuries. Also, swordfights.
Mark