Game Prototype Need coding

I am looking to develop a game prototype. It's a 2d pixel game, It's a monster versus monster game, but I want a tactical tile system similar to fire emblem but on a much smaller scale. It also has card game mechanics; every turn, each player chooses a card they have in hand that will determine their movement and their attacks until one of them dies. I will provide almost all the assets (sprites/animation in a png format, sound, and music). I need help with programming and coding. I'd like to use unity, but ill listen to alternatives. Thank you for your time!