First, there are two main criticisms that I have:
- The Lumiose City Glitch - This is kind of a huge deal, since it's a save-killing bug. (For those who don't know, possibly because they're reading this in the future: Saving outdoors (later discovered to be specific areas) in Lumiose City, then loading that save file, could actually lock up the 3DS. The game was obviously unplayable.) I have no idea how this got past playtesting - or component testing, for that matter, though I don't know how Nintendo/Game Freak/The Pokémon Company coded it, so that breakdown might not work as well. Fortunately, we live in a day and age when such things can be patched. That said, I'm honestly surprised at how long it took them to release the patch. (Also, this is the one time that I'm glad that I got spoiled, since I just avoided saving anywhere within the Lumiose City limits.)
- The controls in 3D areas are a bit weird. It's easy once you know the trick: You can only move forward (usually), and sideways buttons rotate you. The main issue w/ this is that it's unlike the controls for the rest of the game, so the controls in any over-the-shoulder area are always unintuitive.
- So far, the new Pokémon designs are pretty cool. My personal favorite is actually Spewpa, since it's a new - yet realistic - approach to the 3-stage bug Pokémon. (Cool note: Just before the release of the games, a praying mantis made an egg sack in our garden. Like Spewpa, it's just kind of spat/frothed up and then dried.)
- Wonder Trades are awesome. Finally, I don't have to do a bunch of online stuff to find someone with whom to trade, but I also don't feel compelled to overthink things like with GTS.
- The roller skates handle really well, once you get used to them - which isn't very long. Weirdly, they seem to be putting the bike to shame, since they're much easier to don/doff.
- Item registration is much better in this system. In generation V, if more than one key item was registered, pressing Y resulted in a small menu, which had to be navigated up/down if one wanted anything other than the top item. Now, if more than one item is registered (up to 4), a directional menu pops up, making it much easier to select the item w/ one additional button-push. This also makes it quicker to use, since it's easy for me to remember, for instance, that my Old Rod is Y-Up, while my bicycle is Y-Right.
- Berries are back in the game. In generation V, it became a chore to have to make sure that a Pokémon was tucked in, then go onto my computer to go online to the global link, to make sure that I was berry-ing. This was compounded w/ the knowledge that it would only be up as long as Nintendo bothered to maintain the servers, and is further compounded by the fact that Nintendo is phasing out the Gen V Global Link by mid-January.
- Berry growing is changed for the better. Admittedly, having to pull weeds is technically tedious, and doesn't add any game value, but I like the rest of it. I like that I can get random fights against Bug Pokémon that are trying to eat the berries. While there are 2 stages added to berry growth - thicker trunk and buds - this is compensated by increased berry output, so it's all good. The game just plain starts with 36 berry growing spots, and making mulch out of berries is a nice optional. Also, hybridizing berries to get other (existing) berries is a neat way to make it not just an item-hunt.
- Gogoat! I don't technically have one yet (working on it!), but the idea of riding a goat Pokémon still seems awesome.