If the "Learn To Fly" series is good at one thing, it's the ability to create a solid game using little to no extravagant game mechanics, and keeping the games simple, down to earth, but overall making you feel like you've accomplished something while you play them. In fact, that's the core defining part of the series since the very first "Learn To Fly", and it's remained constant throughout every sequel. Funny story premise, interesting character, delightful music that doesn't get boring after a while, and upgrades that massively improve you to the point you actually can see the improvements on the screen.
With "Learn To Fly 4" coming soon, the mechanic that's come since the first, and hopefully, see a lot more to come from Game Developer light_bringer777. With improvements over the "Learn To Fly 3", the game will feature a lot more upgrade variety to make your penguin avatar different with each different playthrough, as well as the creation of a lot of different options for customization, it's quickly shaping up to be the best one of the bunch, and the culmination of everything that's worked so far. Expect it to be out soon!