Imagine Warframe with a coat of Anthem paint and a generous helping of recycled Destiny enemies with awful ai. Then stuff in as many timegates and microtransactions as the most shameless gacha game possible.
That's pretty much it.
The good stuff is competently repackaged from better games, and the bad stuff is typical Nexon. Worth a playthrough of the campaign since it's free, but if you start getting the urge to open your wallet to skip the grind, you're better off just uninstalling right then.