>>34931775Emerald has the same regional Dex, only difference is you can get more National Dex 'mons after beating the Elite Four. ORAS uses a modified version of RSE's Dex with cross-gens.
ORAS is lacking the Game Corner, Safari Game (the Zone is there but it's just a regular route with no gameplay changes, despite Hoenn's Safari Zone being the most mechanically interesting in the franchise due to Pokéblocks), minigames like Berry Blending (you just get a perfect Pokéblock instantly), and a lot of areas were truncated compared to RSE. The area of Granite Cave you need to get to Steven is two rooms, Mr. Pyre's interior is missing two floors, the bike puzzles from Sky Pillar are completely removed (you have to watch cutscenes as you climb instead), New Mauville is almost completely gone, pic related.
Kind of stretches the definition of "removed" but some other mechanics were changed in negative ways. Instead of walking through grass to get soot in Route 113, they reuse the leaf pile code from XY. Sheen is removed so you can feed Pokémon infinite Pokéblocks instead of having to specialize like with EVs.
Honestly, bigger issues with ORAS are the lack of Emerald content (especially their decision not to use Emerald's trainer roster which completely revamped how double battles worked and allowed enemy double teams to have more than two fucking Pokémon; even new double battles in ORAS only use two Pokémon when it's not a plot-relevant multi battle), breaking the flow of the region with a ton of extra teleports, giving the player a lot more overpowered shit than in RSE (including a free Lati@s five badges in for no reason), and the Delta Episode having the worst plot of any Pokémon story arc, full stop.
It also doesn't help that there are interviews where Masuda admits they didn't try at all and tries to deflect it with "kids only care about their smartphones now, so we don't need to include shit like the Battle Frontier or try to give the game longevity."
