1. One of the most interesting things about Anville Town
are the train descriptions. They have nothing to do with Pokemon, they just made these extra train models and had a guy who excitedly told you about that kind of train car (my favorite is the Hyperspeed Train). It was extra work they didn't really need to do but did so anyway. The extra items you can get is also nice and I like that the explanation is that it's a lost-and-found for items the depot worker found left behind.
2. My favorite one of these is for ORAS. You're more likely to encounter the first instance after the Delta Episode but technically you can get this after becoming Champion and having your first encounter with Zinnia (you have to enter and leave your house again I think). Anyway, in the post game go, after leaving your house you hear Birch screaming for help again. He's being chased by a Shroomish so asks you to take a Pokemon from his bag, but this time it gives you a choice of the Johto Starters! Though you don't have to battle the Shroomish, it wasn't as fierce as he thought it was.
Jump to beating the Delta Episode, you hear Birch once more after leaving your house and he's being chased again, but this time by a Machoke holding a box. This time the Starters are the Unovan ones! And once more, you don't need to battle as Birch realized the Machoke is just from the postal service to deliver a package.
Entering the Hall of Fame a second time, once more you hear Birch and this time he's being chased by his wife! Apparently unable to tell his own human wife from a Pokemon (either he's sleeping on the couch tonight or is seeing the eye doctor tomorrow for a pair of glasses, or both), you now get to pick one of the Sinnoh Starters.
3. New Mauville is neat but sadly feels underdeveloped, especially in ORAS. We're told it was originally meant to be an underground city expansion to Mauville but the project was abandoned. Now you'd think the map would resemble something akin to an apartment building, but in Gen III feels more like a lab (though was still at least explorable) and ORAS was just a generator room (with stairs leading down and doors beside the generator being blocked off). Considering the amazing job they did with the new Sea Mauville, I'm wondering if they wanted to do something more with New Mauville in ORAS (hence having visible other entrances) but ran out of time. Well, as I said we at least still have Sea Mauville so it's not a complete loss.
4. Actually my favorite
Horde Battle combinations are the antagonistic ones: Zangoose & Seviper and Heatmor & Durant where instead of attacking you the Horde Pokemon will instead focus on their mortal enemies. It's like walking in on a nature documentary.
Some other neat ones are Roggenrola & Carbink and Tauros & Miltank (semi-confirming GF at least sees them as breeding partners yet still aren't officially in the game code, aka breeding them could result in an Egg either containing a Miltank or Tauros). Wish they did more (well they did but some combination don't quite make sense like Geodude & Makuhita, Wingull & Lotad, and Zigzagoon & Oddish), though a similar odd pairing idea at least lived on with
SOS Battles where you get ones such as Cubone calling a Kangaskhan, Baby Pokemon calling a Happiny or Chansey, Corsola calling Mareanie, Scraggy calling a Fearow, Carbink calling Sableye, Pyukumuku calling Wingull, and let's not forgot Bagon on Route 3 able to call a Level 10 Salamence!
5. It does?! I never knew that!... Wait how does that make any sense, was the PokeNav dropping calls before or something?
6. Simple actually, well simple if you're a programmer. Basically there are 4 spots on Spinda's head which can "move around". Each Spinda have a unique 8-digit hexadecimal code and every two digits of that code decide the placement of the spots. It's easier to see in work than explained,
this app shows how it's done with the original Gen III sprite. It's probably a little more complicated with the 3D models as they would have the place the spots on the texture map, but a programmer shouldn't have too much problem doing that.
7. There's a few special ones, the one I distinctly remember is that bringing a Togepi to Cerulean Gym will have it "cry softly", referencing Misty's Togepi.
8. Same thing happens with
BW's Badge Gate!
D'oh! Well, my point still stands not all gens had fossil Pokemon.