This is a 2D Platformer game created with Unity 2019.4.20f1. The project contains the solution that can be imported into Unity as well as the compiled game. The executable file is in the /Builds/Windows/x64/Alien Invasion x64 folder.
The game features a main menu, a main level (where the player battles against the alien invasion), an upgrade menu (where the player can upgrade his health and speed attributes), a game over screen which appears when player's lives reach zero and an end game menu which appears when the player has successfully gone through the three waves of the invasion.
This game was created by Konstantinos Loukas with the support of the Brackeys development team (grateful for their excellent tutorial videos) and is free to use for anyone willing to expand and/or commercialize the product, though I will advise you to watch Brackeys' development videos and create one for yourselves (that way, it will be less like stealing and more like creating your own game from scratch and acquiring some hands-on experience ^_^).
All assets included are Free-To-Use for any commercial or other use.
The assets that were used were included in the 2D Mega Pack which can be found here: https://devassets.com/assets/2d-mega-pack/
You can also find this game on itch.io: https://kostasloukas.itch.io/alien-invasion