The first program I worked with was greenfoot. It's essentially java with some modifications, and it allows for the easy creation of games and simulations. One thing that's nice about greenfoot is the ability to edit code in an embedded editor, as well as test it easily within the program. I basically made a quick reskin of his "Trick the Turtle" game, with wasd & arrow key controls, as well as an extra objective: to eat the dinos and protect your babies.

Greenfoot tutorial Joy of Code episode 1 by Michael Kölling