I have mixed feelings about this game.
On one hand, it seems somewhat childish: bright colours, smiling clouds, cheerful sound loop, giant font, handwritten text in background, typos, emoticons nearly everywhere…
On the other, it does show some potential: most of all the last sequence with the burning houses and broken city, also the diversity of minigames (the included Pong game is quite neat easter egg), and your sense of humour is also a plus.
However, you need to ask yourself, what is the true content of your game? If everything was gone and only one thing should stay, what would you want it to be? And once you answer that, add more of it in the game.
So far, the game is mostly about slow walking (or "sliding", since there is actually no walking nor jumping animation). Outside of house → house → computer → bus → riding the bus → outside the city → the city → a shop → YOUR ACTUAL MISSION and before you even realise it, you are back to walking. Imagine it as a movie or book – would you watch a movie that consists mainly of walking somewhere?
"Exploring" is fine, but even in exploring you have to put some gameplay, not just static images (e.g. opening drawers and finding something funny/interesting inside, new set of clothes you can wear in the wardrobe, "fishing" in water – any kind of interaction with the environment, really).
And the actual missions should be way longer. They are probably meant to be the core of your game, yet just when I though "yay, platforms!", I reached the end. You also don't have to put advice everywhere. Sometimes it's useful ("Click to continue"), but sometimes unnecessary ("Jump", "Try not to fall", "Don't use calculator").
As I said above, I liked how the city changed in the end. There are games which include repetition (= going to the city here), so you get used to something and then it turns upside down. That's good. Meaningless repetition should however be avoided.
There's quite some space for improvement here, but it is a good start for making a pretty neat game.
Oh, and I just noticed that you're fourteen, so it's actually pretty great you managed to start and complete a project of this size. Hopefully what I said above will help you to improve.
Good luck with this or anything you decide to make in the future.