I have mostly positive, but still mixed feelings about this game mostly because of it's Early Access status. It's not that the game is buggy or unplayable. It's the contrary, this game is fairly polished and without glaring technical issues. The problem with this game comes down to the underpopulation, which is usually a problem with multiplayer only Early Access games.
OGAT is a fast paced game despite being a rather technical, strategic team game. Round timer is 5 minutes and games can be over quicker than that if the offensive team completes whatever their objective is. Each class has a set primary weapon, secondary weapon and varying numbers of equipment items. There is no way to switch out of your default class set and you have a finite amount of magazines for each of your weapons. It is important to note that I said magazines. In this game, if you reload prior to emptying your current clip, you lose all of the remaining ammo. So don't go shooting a couple of times for a kill then reload. You'll end up running out of ammo and will have to go on a literal suicide mission to get some more.
The maps are asymmetrically designed to suit the strengths of each side. Maps start out lit in favor of the Guards. Lights can be switched off or on to give each side an environmental sight advantage. There are vents that can be used only by the Thieves but Guards can still shoot into them if they see a thief run into one but vice versa also applies. The other movement limitation that applies to the Guards seems silly to me. Guards cannot pass through a broken window. I would undertand if it was a size issue, but there is a Juggernaut class for the Thieves and he's larger than the majority of Guards and has more health and weaponry too. The Juggernaut should abide by the same movement restrictions that the Guards have.
The balance of the classes will take some time to figure out because of the many factors involved. Each class has a different movement speed, different weapon set, different max health value. That's keeping it simple because you have to analyze each weapon's balance too. Each weapon has max damage, reload, rate of fire, ammo(capacity) and magazine count stats. I noticed, like other tactical shooters, your shots will spread to the left or right of your crosshair if you repeatedly fire a weapon for longer than 3-4 shots. I like that it's a factor in the game because despite being a top down shooter it adds to the tactical element and technique needed to successfully aim your shots. The equipment covers your usual tactical pieces of equipment: flares, grenades (frag, glue, incendiary, smoke), healing syringe, molotovs and stones. They are planning to add a few more, so don't worry about the lack of flashbangs, because they are planned for the future. The currently provided equipment does a good job of controlling space. Can't see around the corner because of darkness? Throw a flare over there and spot that sneaky thief. Guard watching the exit of the vent shaft you plan to pop out of in the light? Smoke grenade has you covered. Need to slow down that thief approaching an escape? Glue grenade will slow that thief down to a crawl.
There are multiple game modes besides the eponymous Guards and Thieves mode. Soccer, Zombie Rush, Team Deathmatch, Instagib Team Deathmatch, Bomb Defusal, VIP Escort, Capture the Flag, Instagib Capture the Flag, and Mad Ball. There is work currently going on for a few additional modes as well. Hosting games is easy enough and the admin tools are fair. You can choose the combination of game mode and map that you wish to host, friendly fire (on or off), team swap, auto-balance, player kick.
Now the one downside of this game is its current popularity or rather a lack of it. I haven't seen more than 150-200 global players logged into this game at once, even during primetime western hemisphere gaming hours. Even when it has reached over a 100 players, usually between 50%-66% are in game. For as easy as it is to host in this game, that is inexcusable. You'll even see host in the world chat room asking for players to join up to populate their game.
Overall, I'm mostly positive on this game because of all that it has to offer. If the community grows for this game it could be a hit. Otherwise, this game is not going to last for too long without the support of a good community. I'd like to see this game do well and it would be a blast to see this game streamed among friends.