Pokemon arrives to a brand new handheld, but the mechanics remain the same.
New Gameplay Mechanics:
1) One of the main differences between Pokemon D/P and its previous iterations is the inclusion of online. Using Nintendo Wi-Fi you are able to trade pokemon wirelessly through the GTS (Global Trade Station). The main problem with the GTS is that you can only search for pokemon that you have seen, which severely limits its use. Using Wi-Fi, the player can also battle wirelessly using Friend Codes. While troublesome there are many ways to find people to battle (gamefaqs has a trade/battle board).
2) Since the 2nd Generation, each new generation has introduced some kind of new gadget to aid the trainer on their quest. In diamond and pearl you are able to get a poke-tech, which is basically a fancy watch. During your travels trough Shinoh you can find new applications for the poke-tech like a digital and an analog clock, a timer, a counter, and a roulette application. While most of these applications are useless, some of them can come in handy like the counter, which you can use while EV (effort value) training so you can keep count of the numbe of EVs you have gathered.
Now i will go into detail on some features of the game
1) Sinnoh - - Sinnoh is the region where Diamond and Pearl take place. Sinnoh is a more norther region when compared to pervious ares, which cause there to be more variation in the climate. In Sinnoh you there is a mountain range that divides the continent into two different areas. In the northern part of the map there is an area that is covered by constant snow fall.
2) New Pokemon - - Diamond and Pearl feature over 100 new species of pokemon. Of those 100+ species there are a ton of legendary pokemon to catch.
3) Community - - Since its release pokemon has always had a huge following, and it continues to this day. Nintendo has supported the fans of the games by giving away free rare pokemon at local gamestops and toys r us. Pokemon also has a huge competitive battleing community. With sites like smogon, helping to shape the metagame, pokemon can continue to grow and develop.
Pros / Cons
Pros:
1) 20+ hour story
2) 200+ hours of game play ( i have put in about 300 )
3) Introduction to competitive - Wi-Fi allows more players to experience the competitive nature of pokemon.
4) Deep RPG - 493 Pokemon, 90ish TMS, EVS, IVS
5) Wi-Fi
Cons:
1) Still the same old pokemon
2) Graphics look all right, but not that great
3) Sprites of pokemon still look great, but the moves need to be aligned to each sprite (ie: Infernape's Flamethrower doesnt come from his mouth)
4) Even after all these years, the series is still viewed as "kiddy"