This sprite acts as a spawner, and will spawn 1 of 2 sprites when a certain condition is met. You can define the sprite numbers, whether they're vanilla or custom, the condition that is used to determine which sprite to spawn, the logic for meeting the condition if it takes a parameter ("Equal to" or "Greater than or equal to"), their spawn state, and XY offsets with the extra bytes. You can also optionally enable an additional 12 extra bytes (for a total of 24), and set extra bytes for the spawned sprites and set initial speeds by using the "extra bytes extender" sprite included.
There are a lot of configurable settings for this sprite, all of which are described in detail in the spawner's .asm file. I strongly recommend reading through it thoroughly first, to make using the spawner easier. 2 screenshots are also included in the zip to demonstrate how the extra bytes could be set up.
Note for anyone using the Fast Retry patch along with this.
If you are using the Midway Cleared condition you will probably need to change the code used to detect if the Midway has been cleared. I changed it to this and it seems to work fine:
;;start of added code
;;end of added code
;;LDA $13CE|!addr - this is the original lda that no longer works when you use the retry patch
Had to submit an updated zip folder, since the .json files were incompatible with the latest version of pixi. Regardless of that, all of the options I tried out worked out well and it was fairly easy to use, once I got the hang of it. Definitely a ton of options to use and nothing I tried broke, so it's accepted. The added screenshots are also incredibly useful, so thanks for including that.