Well for starters, you buy the game. Insert into you Nintendo DS slot 1, boot the firmware, execute the game and begin your turnabout trials. As for gameplay. 50% of the game involves "problem solving" in the court, the other half is doing detective work, digging up clues, using scientific method (only really prevalent in case 5 of game 1 and the last 3 cases of game 4 - Apollo Justice), and cracking people's hidden secrets (Phoenix Wright 2/3/4 - using Phoenix's Magatama, and in Apollo Justice - using Apollo's bracelet). The game plays out like a visual novel. You walk around listening to people's conversations and answers to your questions while putting the pieces into place for each case. Endnote: The game itself explains what is required of the player to complete each part of the case in sometimes explicit but usually implicit ways. As to beating the game, just solve every case or... buy the original Gyakuten Saiban games for Gameboy Advace and insert it into the DS slot 2 of the respctive games to allow case jumping.

He unknowingly submitted evidence that had been forged.

So far as we know, no, he does not die...

However, it never does tell you about his fate in Ace Attorney: Apollo Justice. For all we know in that vague game, Kristoph Gavin could have poisoned his tea...

But I highly doubt it. He is probably travelling the world with Franziska at that time frame.

There's Professor Layton VS Phoenix Wright... and Ace Attorney Investigations Miles Edgeworth 2(cameo like the first), and hopefully a Ace Attorney 5.

Currently, there are four Ace Attorney games:

1. Phoenix Wright: Ace Attorney

2. Phoenix Wright: Ace Attorney - Justice for All

3. Phoenix Wright: Ace Attorney - Trials and Tribulations

4. Apollo Justice: Ace Attorney

Recently, the release of a fifth game has been announced, yet again where the protagonist is Phoenix; however, the game is set one year after the Apollo Justice game and Phoenix is a much older guy. There are also two games in the Miles Edgeworth Investigation series, which is simply where Edgeworth is the protagonist and you investigate crimes without going to court.

um, i don't think you really can, but at the menu there should be a "New Game" button which should let you play the cases you already beat..? I think. xD

Choose new game and scroll to the case you want.

Not in any of the games, but they do in some fanfictions.

It is Implied that they have some sort of feelings for each other

He's outside of the Gatewater theme park on a boat with Maya and Pearl.

You cannot proceed with the game if you have not received all the evidence. The evidence acts as a trigger to continue the story.

Phoenix was proven innocent in Ace Attorney, but no further games have been published since then. He mentions wanting to retake his bar exam, so it is possible that he could get his badge back in any future games made.