Mini Metro is a puzzle masterpiece that puts you to the task of building metro lines between various stations in order to get passengers from station A to station B, which each station differentiated by its shape. Passengers at Triangle station might want to get to Square or Circle station, and they take automatically moving subway trains to get there. Over time, more and more stations pop up and you get various items to help you keep your stations from being overcrowded. If too many people stay at the same place for too long, you lose. There are plenty of levels to try your metro building skills on and I've really enjoyed it.
The game starts very simply, with only two or three stations on your map, and you connect them with a single train line. Trains more automatically back and forth on your lines, picking up passengers as they go, if it makes sense. As time goes on, more stations appear and you need to either add to your existing lines or build new ones. You can edit your lines a bit - although I've had difficulties making lines go the way I wanted and I wish the game was better in that sense - and make them as big as you want. However, the longer you make a line, the longer it takes for your trains to go back and forth, so people wait longer. Time moves while you play and each week you get new items to help you. Items range from locomotives, train cars, new tracks, tunnels, or other rarer items like station upgrades or faster trains.
Eventually, you get unique stations with special symbols - Stars, Hearts and the like - so you need to plan well for your trains to bring passengers closer to them. The odds are stacked against you and eventually your stations will overflow, netting you a game over. You can unlock the next challenges by moving 500 people through your transit system, so that's the objective for each map. Maps get a bit more complex, with various restrictions - such as your trains only carrying 4 passengers each, or having a lot of islands to make you be more careful with your tunnels. When you lose, you can see the whole progress of your game and save that. You can then continue in endless mode which removes stations overflowing.
With daily missions and a bunch of puzzle maps to go through - not to mention the harder or easier difficulty modes - there is a ton of stuff to do in Mini Metro, it's super well designed and I really loved playing it. it's relaxing and has the 'one more turn' feeling of games like Civilization. I've completed it entirely and would recommend it to any puzzle fan.