This generator will spawn Sprites (configurable) on the right side of the screen at the low tide height. Additionally it makes the tides more dangerous by pulling the player additionally downwards (also configurable). Using this without SA-1 is not 100% recommended, it will cause slowdown really fast.
Your level must be at least 3 screens long, else the generated sprites will always float upwards. You must use the Layer 3 Tides (low only) or the Sprites will spawn in thin air and do nothing.
How to configure stuff is included in the ASM file.
Example usage: https://www.youtube.com/watch?v=CAAN8rbiFdA