>>26964827No Battle Frontier, no Emerald locations like Mirage Tower, no Safari Zone, no Gym Leader rematches, no Game Corner, areas like Granite Cave/Mt. Pyre/New Mauville are super shrunk down, less Trick House puzzles, Mallville, they like doubled the amount of route gates (though this is the fault of the engine more than a design choice), more handholding, Gen 6 Exp. Share (the big puzzler is them giving it to you even earlier than in Gen 3, when you already can get it after like one badge in RSE), mandatory gift Lati@s, using the RS rosters for trainers like Tate&Liza, using RS's double battle locations instead of Emerald's in general, and everything about the Delta Episode except the admittedly awesome climax.
The double battle thing is something I think more people need to bring up, it was one of Emerald's biggest improvements from RS but it's always overlooked. Every pair of double battle trainers in RS are planned that way, and you never have more than two Pokémon total between them, most notably with Tate&Liza. Emerald completely revamped how double battles worked, allowing multiple individual trainers to team up for double battles if you caught their eye simultaneously, and you could end up with double battles against up to six Pokémon (I definitely remember going against at least teams of five in double battles this way).
Why ORAS ignored this huge QoL change that was permanently adopted into the series for later games, going back to the RS model (except for multi battles, but you're always given an OP partner for those), is one of the most baffling decisions in the game, it's like the dev team literally didn't look at Emerald once while making it until the very end when they needed ideas for Delta Episode events like the Mossdeep takeover.
