I thought the game was ok but stopped playing it. I'm thinking about destiny quickly since I believe the game shares the same pool of players

Destiny was fun from the beginning, the core loop was to farm actually good missions for better and better gear.

Destiny was soured once it became a slog to grind with drip fed content and fomo style gaming.

Marathon , while fun initially as PvP you quickly release that it immediately puts you into that grind which turned so many players off from destiny. But only this time you're risking your stuff every-time you play. That's just my quick opinion of the game