While the game already has a password system to save progress, this new patch by BillyTime!Games is a much more elegant solution – especially on FPGA-based systems, where save states aren't currently available across the board.
The patch saves the game automatically when you start a new level or lose a life. To load your save state, you hold 'B' and press 'Start' on the game's title screen. Keep your finger on the B button as you select your character, and the game will pick up where you last left off.
This might sound like a minor fix, but it's one that we personally can't wait to use on our Analogue Pocket.