Sure! Here's an example of a simple game that meets your requirements. This game allows players to move using the WASD keys and place portals using the spacebar. It uses pictograms for the visuals and JavaScript for the game logic. The portals will teleport the player between them.
To play the game, copy the code below and save it as a single HTML file. Then, open the file in a web browser on your smartphone.
Once you have saved the code and opened it in a web browser on your smartphone, you can control the player character using the WASD keys. Press the spacebar to place a portal at the player's current location. You can then move around and teleport between the two portals by walking into them. Have fun playing!