Although progress with incorporating the new battle engine is currently on hold, I've been at work with making some minor tweaks with Sigma Emerald. The wait for the completion of the disassembly provides (very) plenty of time to refine what is present before adding more new stuff into the game. Upcoming changes will include minor wild encounter tweaks as well as music changes in a few areas.
I have addressed this concern for the next update. Wild Unown will be found in the inner portion of the Sealed Chamber (after the player uses Dig) and gives the chance for all variants to be caught :)
Thanks for the clarifications. I'll try looking further into the issue with this move, though the bug merely slows down the gameplay.
1. A challenge mode will be considered once the project is finished. It'll be tough trying to maintain two different branches whenever there are new features to be added.
2. Will be easier with the new engine, as there will be less of a need to add new routines into the ROM individually.
3. The plan is to add cross-gen evolutions and keep everything else as-is. (and rearrange the Pokedex accordingly)
4. Like #2 and #3, will be more seamless to implement once the new battle engine is here.
You might want to consult Tlachtli regarding this, as he was the one who fixed the PRNG in Sigma Emerald.
Specifics please?
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EDIT: v1.9 has been uploaded, bringing updated cries consistent with Gen 6 onward. Refer to the changelog for the full list of changes.
Additionally, the encounter sheet has been updated with the latest tweaks to the locations of each Pokemon (wild, event, and in-game trade)