Game Brainstorm

So I need four ideas for games.

One of them is a 2d (Now probably going to be 3d because of Unity) game with two worlds that interact with one another based around Fire and Ice. You play as a Fire Person in an Ice World and an Ice Person in a Fire World. Actions you take in one world affect the other. I had this idea long ago and it would have a similar art style to the game Fire And Water. There is a similar system in that game where one player must press a button in order to let another player through, and they can press a separate button to let the first player through. However in my game you would be on your own, and have to press a button to switch the worlds and alter the objects in both worlds.

Engine: Unity

Another one... is... come on brain... think of things...

MEDIEVAL ADVENTURE

Yeah sure that works.

You play as a character who's only weapon is a sword going out into the world for the first time. You are immediately defeated by a slime. Game over. Just kidding. Two other people come to your rescue and you form a party, which is really what the game was about in the beginning- hah I tricked you. You will pick up more companions as you continue on your quest, and you will be able to switch them out at your leisure. Each of the companions would be different and have a specific skill set. You might need one companion to help traverse a volcano and another to help swim across open water. There would be a final scene where every companion you've gathered helps you defeat the Big Bad of the game, and I'm sure I would somehow make it heartfelt. There would be around... maybe twenty characters?
Each of them would have their own abilities, design, plot, personalities and dialogue. So, that would be a lot of work. Although I guess only nineteen dialogues as the main character, that is you by the way, would only have Yes, No or other options, and not really have to speak at all.

Engine: Unity

Uhhhhhhhhhh... Music... Explore... Digger...

Ok now to make a game using those three words.

You are a player with a pickaxe and you need to dig to the center of the world for... reasons... There is music playing and you have to swing to the beat. Well you don't have to but you get more points and will go much faster if you do. This sounds more like a mobile game, something like flappy bird. Maybe I'll make it so that if they aren't on beat they lose. I'm sure that would destroy a lot of screens. There would be a lot of customisation too, able to change what your pickaxe looks like and what music you listen to, maybe change what you're breaking too.

A RuneScape Pickaxe

Engine: Unity

FINAL GAME

AND THIS IS ONE I MAY ACTUALLY BE ABLE TO DO

A freerunning game where you, the player character, has to run across  rooftops in order to escape Something chasing you. There will be obstacles in the characters way, such as roof access stairs and clothing lines. 

The character will be wearing something simple, a green hoodie for example. But you can customise it by changing the colour and putting a logo on the back. It would probably be similar to several other chasing games but I'm sure I can find some way to make it unique, maybe with the various power ups I could implement and have a story to it. Maybe little hints as to why you're running, with the thing that is chasing you exclaiming or shouting things that will give away information on what the runner's background is.
The character is based on an idea I had for another character for a story who is basically Spiderman if he was a villain but still had the same joking personality. This character has many powers, which is useful as there will be an excuse for many powerups that the Runner can use.

Engine: Unity

An Example Of Free Running