Sure, here's a simple implementation of a game that resembles Geometry Dash but includes portals. The game is designed to be played on a smartphone and uses pictograms for visuals:
This is a basic implementation of the game concept you described: Portal Dash. The player (represented by a red rectangle) can move horizontally and fall due to gravity. The objective is to avoid colliding with the green portal rectangles by jumping over them. The portals move towards the player and new portals are generated as the player progresses.
Please note that this is just a starting point, and you can enhance the game mechanics, add more levels, customize the visuals, and refine the gameplay further based on your requirements.