Gateways from a first glance seems like your average 2D puzzle platformer, along many of its kin. The name itself also implies that it has quite a lot in common with Portals, where you can teleport from one place to another. Would that be sufficient for a 2D puzzle game? I'm not sure. Is that all this game has? Hell no! :D Gateways has some quite interesting gameplay puzzle mechanics, that can be tough to wrap your head around later on. Apart from your standard portal device, you also get to resize yourself, rotate the world, or create a portal through time and act alongside and work together with the actions of your past echoes! And later on, you get to use all of these at the same time to solve the puzzles laid out in front of you. Luckily, even though the main game is easy to complete in my opinion (apart from the last few puzzles where you get to use all devices at the same time), there is a way to load external, user made maps - and there is a map editor for Windows with which you can create your own. Overall, it's not exactly Braid-levels of excellence, but still pretty damn interesting and enjoyable.
The GOG version lacks the key feature of the SteamWorks match making server, which means multiplayer is only through direct IP connection.
