Unity or Game Maker Programmer

Hi, I need someone to code our game. It is a 2D with similar mechanics to Speed Runners; I'll provide all graphic and sound assets (such as music, sound FX). The game is designed to have these critical functions (If you get hired, I'll give the complete game details): * Story mode (single player): This will be a campaign in which a comic must appear at the beginning of every mission. It will not include saving tasks, as it will work similar to old arcade games, where if you lose, you will have to start from the top. However, every level must increase the opponent's difficulty (AI), and the obstacles must make the game harder. It will only be 5 "levels". * AI: As mentioned above, the game must have a basic-intermediate complexity of AI (simple decision tree, not machine learning or similar stuff) for the opponents; you may get a similar reference on all AI's of similar games like speed runners, Mario kart, etc. * Local multiplayer: There's no better way to exemplify it than giving you an exact reference of how it will work. If you look at how speed runners' local multiplayer mode works, you'll understand it completely. It won't be split screen; same screen, same scenery, same area, just the functionality to let players control their character on the same space. It will be on the same device (pc, xbox, etc) so there's not a single networking function on this project (as for now). * Gamepad available * Exporting: For the moment it will only be available for PC (it will be published on Steam) but we might decide to make it available for major game consoles such as Xbox One, PS4, Nintendo Switch, etc. So, because of this, the game should be made on a game engine such as Unity, Game Maker Studio 2 (If you own the licenses), or a similar platform that simplify that exporting task. * Physics: It will have some slight personalized configurations for physics, but I know it will be matter of just modifying a variable's value. * Menu: Should let the player choose to play the story mode, custom match (local multiplayer), go to game settings, or exit game. In the custom match selection, it must lead to another screen where the players may join (up to 4 players) choose their character and the scenery. At the game settings screen, the user may choose the frame rate (fps), resolution, music volume and sound FX volume. * Screen resolution's resizing: As mentioned above, the user may choose the screen resolution, but it also must have an automatic resizing, to make the game fit automatically the screen's resolution. Some minor details may come, but I assure those are the major-difficult ones. I'm attaching our GDD so you can understand a little better our idea. It’s important that you consider that this project won't be our last one, so if you do an outstanding work, we may have a long-term relationship for future projects. Please send reference of similar projects you've worked on the past. Regards, Santiago