This is how our Heroes made it to Sonic's World and they Rescue Amy in Ryan's Quest.
[They're in Eggman Ship, wondering around and they saw Sonic surrounded by Heartless]
Sonic: Need some help!
Ryan: Let us handle them.
They are fighting them and they defeated them
Sonic: Thanks. What are those things?
Ryan: Those Heartless. They were trying to take People's hearts.
Sonic: Heartless? It's what you call them? I just saw one of them in Eggman's Lair.
Sonic: He's the Scientist who wants the Choas Emerald. And I have to get them back and save Amy.
Ryan: Can we help you?
Sonic: Yeah, let's go.
They went off
Eggman: What!? Are you saying that Amy is not one of the Seven Princesses?
Eggman: After all, the trouble we capture her? And why are those seven? What are you planning anyway?
Kaos: Because this is for the last Keyhole. You could tell this stupid thing to Cody.
Eggman: Well, we're wasting our time. The Heartless has been devoured the Girl heart, and I have to say that's she's lost forever, Kaos.
Kaos: Oh well. I hope you could find the Keyhole in this world before...
Then the Alarm has Ringing and Eggman noticed Sonic is here now
Eggman: That Hedgehog is here... Choas, I want to eliminate him.
Choas: So, you want me to get rid of the Hedgehog? I'm sorry, but my contract said-
Eggman: I know! You think I don't know!? I wrote the Contract! I know it's said you want to capture Amy and bring her here. But you have fight Sonic, okay? It just like said, you can do whatever you want, so do it right now!
Eggman: Well, it looks like he fall for that one. But for some reason, I hope doesn't get hit from that thing.
Our Heroes went off and they Saw Choas
Choas: You must be Sonic?
Sonic: You're Choas, aren't you?
Choas: Yeah, that's right. And I'm here to fight you.
Sonic: Why you want me to fight you for?
Choas: None of your concern, let's fight!
Sonic: Alright, you ask for it!
They are fighting him and they defeat him and then Giant Robot appeared and hit Choas
Eggman: Sorry, Choas. But I think the Deal is over now.
Sonic: Eggman, where's Amy!
Eggman: Right here!
He's holding her
Amy: Help me, Sonic!
Ryan: Eggman. Let Amy go or I'll use my Keyblade on your butt into next week.
Eggman: You must be Ryan F-Freeman. I got the Heartless and Sonic's metal counterparts. Get a loud of this!
He summon Metal Sonic
Eggman: Metal, defeat those heroes.
Metal Sonic: Accepted.
Sonic: Here we go.
Ryan: I'll summon Po the Panda, Odette and Midnight Sparkle. Light!
[Ryan summons Po, Princess Odette and Midnight Sparkle and his friends disappeared]
Po the Panda: Hi, there Ryan!
Odette: I'm here to help, Ryan.
Midnight: Ryan! Like me to help?
Ryan: Yes, Sci-Twi. Or.. Midnight.
Midnight: Just call me Midnight.
They are fighting Eggman and they defeated him
Eggman: Metal, Please protect me!
Metal Sonic: Actually, I won't.
Eggman: What? Why?
Metal Sonic: Because... I'm getting rid of you!
He throw him to the Ocean and Eggman is chasing from the Crocodile
Eggman: Oh no. (scream)
Odette, Po and Midnight Sparkle disappeared and Ryan's Friends has appeared
Sci-Ryan: Whoa. What just happened?
Ryan: Nothing. And look!
They saw a Keyhole, Ryan aim it and they did it
Amy: Sonic, are you going to leave now?
Sonic: Yeah, but don't worry, I'll see you again. And tell you what, I'll take you to the Amusement Park, someday.
Sci-Ryan laugh, then Tail give him a Serious Look, he stop him for laughing
Sonic: Oh, boy. Tails just want to come with you. Do me a Favour, look after for him will ya?
Ryan: I will.
They went off and they saw Choas and Metal
Ryan: Hey, are you two okay?
Choas: Yeah, we are.
Ryan: So anyway did you work with Eggman for?
Choas: My friend is looking for someone, Eggman promise me.
Evil Ryan: Promised you what?
Choas: To find the Person named Sephiroth. I help him to exploit the Darkness, but it went backfired. He fell into the Darkness and couldn't find the light.
Ryan: Don't worry, I'm searching too.
Choas: For his Light? Don't lose sight of it.
Ryan: Sure, and what about you Metal?
Metal: And I work with Eggman to help my friend. He and his friends lost his world, and I want to help him. After his World has taken over, I have nothing else for him.
Ryan: Don't worry, I'll help you for him.
Metal Sonic: Really? Well, don't make it worst for yourself.
Ryan: Hey, if you want to see your friends again. Make sure you don't have Darkness power within you, Choas.
Ryan: And for you, Metal Sonic. Make sure you can some friends with Sonic and the Others.
Metal Sonic: I think I'll pass.
Ryan: Ok. See you later. Tell Tino I said Hi.
They left this world