As for the tech: it's all TypeScript + HTML5. I did not use a game engine; I just made a game loop with setTimeout and the artwork is all just png's drawn on the canvas. The sound is played through the HTML audio API. Input is watching keyboard events and the Gamepad API.
One thing: I know this is 2023 but it's not a game for phones. It's for a laptop or desktop PC with a physical keyboard. It also works ok on an iPad with a physical keyboard.
Tippy Coco is free and without ads. The code is available (MIT license) at https://github.com/malgorithms/tippycoco
