Special Demo Version

If you managed to get a Special Demo code for the game, you can star your next Hoenn region adventure early. The demo features gameplay that you won’t experience anywhere else. You can also bring a specific Pokemon to the full game, as well as the reward items that you acquired during your short demo adventure. Unlike most demos that you can play only for a limited number of times, Pokemon OR/AS's special demo can be played as many times as you like!

Demo Details

The demo takes place briefly in Mossdeep City where you'll get to choose one of the LV35 starters: Grovyle, Combusken, & Marhstomp. At their starting level, they're almost ready to evolve to their last form. Later on, they'll receive their Mega Stones, and they'll also be able to learn their ultimate moves (Frenzy Plant, Blast Burn, and Hydro Cannon respectively)

In the demo, you'll get the chance to capture a Glalie or Steelix that can now Mega Evolve. However, Steelix is only available to Japan while the rest (NA, EU, AUS, and KOR) can capture Glalie.

After completing the first part of the demo, players can go on more adventures by talking to Steven. This may include different objectives like finding a Pokemon, searching for a lost child, or defeating all trainers. These tasks will change per playthrough. One thing to note is that you can't save in the middle of a playthrough. You don't have to worry though since a usual playthrough may only take around 10-20 minutes. The Pokemon's experience also resets after every adventure.

You'll get rewards for completing a set number of playthroughs. During the 5th and 10th playthroughs, you'll encounter Elders with more powerful teams. You'll also see characters or random NPCs in Mossdeep City. The rewards are only good up until your 10th playthrough and/or after completing a secret mission.

Secret Missions

When playing the demo, there is a small chance that you'll trigger one of the two known Secret Missions in the demo. The first one will make you go to an island devoid of wild Pokemon encounters. However, this island is occupied by Team Aqua or Team Magma members that you need to face. Fortunately, May is there to team up with you and lend you a hand. There are no new items for this mission but new battles only. This secret mission can be repeated by talking to Steven and selecting "Let's go somewhere secret"

The second secret mission will take you to another island in search of a suspicious man. If you search the forest, you'll find this man in the corner of the maze-like area. Talk to him to receive a Nugget that can be transferred to the main game. Completing this rare secret mission will open up more areas in Mossdeep City, including Steven's house.

Demo Rewards

Transferring the Rewards to the Full Game

You need to use PGL (Pokemon Global Link) to transfer the rewards you got from the demo and Glalie to your full game. You can do this by doing the following:

1. Talk to Steven in front of the Pokemon Center and select "Send to Full Game"
   
2. Select what you want to send then press A again to confirm.
3. Launch the full game and select Pokemon Link.
4. In the next screen, select Yes.
   
5. Once done, you should see a confirmation if the transfer is successful.
   

Reference and Image Source

Additional Resource and Images: Serebii.net