I have been working more on the coding side, and I've learned enough to add a new feature where you can select any level to practice.
Jumpman-2016-v1_0.atr 90.02KB 160 downloads
There's now a new item in the main menu. Choosing the "practice a level" option will give you a new menu to select any level. This new menu operates a little differently because using Option to step through one at a time would be too slow. Instead, you use the joystick to highlight a level number and press Fire to start that level. Once you get done playing the level, it short-circuits the end-of-game score and high score table and sends you back to the Practice a Level screen. Use the Select key to return to the main menu.