At first glance, Overwatch is a simple team shooter. Two groups of six, taken from a cast of 21 multifarious heroes, vie for control and momentum in four standard game modes. As the hours go by, though, Overwatch displays new layers–not just in how matches unfold, but in how different characters interact, how small actions contribute to the bigger picture, and how many ways there are to play. This process of discovery doesn’t appear to stop, either–even after 50 hours, I’m still learning Overwatch’s intricacies. Though it seems simple at first glance, Overwatch becomes a seminal team shooter the more you play.

Overwatch is somewhat of a time machine, travelling back through the history of the shooter genre and borrowing ideas from iconic shooters throughout the years: the fluid arena combat of Quake; the cutthroat precision of Counter-Strike; the dynamism of Titanfall, and the reflexive firefights of Call of Duty. But Overwatch isn’t a slave to its influences–it refines them into something more. By standing on the shoulders of giants, Overwatch has crafted a fresh, modern, complex experience that displays a confidence in its various elements, and how they all flow together.

This ever-changing experience hinges on the quality of its colorful cast, and in this respect, Overwatch has delivered with every hero. Genji darts over walls and past enemy defenses, whipping ninja stars and slicing through defense turrets with his sword. Pharah flies over the fray, raining rockets down on key control points and hulking tank characters. These are characters that could have entire games designed around them.

What’s amazing is that, despite how different each hero is, they clash, interact, and cooperate in compelling matches. There’s always some way you can contribute, whether it’s covering your team with Reinhardt’s massive shield, or disrupting the enemy offensive as Tracer, flitting in and out through time and space, pestering opponents before you warp into the next room and away from the skirmish. Overwatch’s social mechanics encourage teamwork: a post-match voting period lets you choose your MVPs, based on factors overlooked in other shooters such as the amount of hitpoints healer Mercy replenished, the number of energy barriers Zarya projected on teammates, or the time Lucío spent buffing his cohort’s movement speed.

Overwatch’s maps are designed to give the combatants areas and scenarios in which they excel. There are crucial choke points and varying sightlines throughout: the foundries of Volskaya Industries create tight corridors and vital elevated positions, close-quarters battles and long-range standoffs. Overwatch combines the intricacies of its environments with the complexities of its powerful cast. It refines what could easily have been chaos.

But Overwatch’s strongest aspect is how it manages to constantly teach you something new. Each match reveals another detail you might have previously ignored–the audio cue that signals McCree’s lethal Deadeye attack; the sound a stalwart Bastion makes when entering its dangerous turret form. Playing Overwatch is a digging process, and finding new layers is part of what makes it special. It’s not impressive that Overwatch tries so many different things–it’s outstanding that it succeeds in every attempt.

From the dozens of hours I’ve played in Overwatch’s betas, it’s clear that developer Blizzard has crafted a fantastic shooter worthy of praise on numerous levels. It manages to maintain focus, despite the complexities and variety of its cast, locales, and interlocking systems. However, because Overwatch’s servers only went live today, we’re holding our final opinion until we’ve tested the game on PC, PS4, and Xbox One in real world conditions. If all goes well from a technical standpoint, Overwatch stands to be one of the best shooters in years.