-Short- A Platformer 
@Stage\n\n@Sprite1\n\nwhen flag clicked\nswitch backdrop to (backdrop1 v)\nswitch costume to (costume2 v)\nshow\ngo to x: (-230) y: (-141)\nset [x v] to [0]\nset [y v] to [0]\nforever\n    change [y v] by (-1)\n    if <key (left arrow v) pressed?> then\n        change [x v] by (-1)\n    end\n    if <key (right arrow v) pressed?> then\n        change [x v] by (1)\n    end\n    set [x v] to ((x) * (0.9))\n    change x by (x)\n    if <touching color (#000008)?> then\n        change y by (1)\n    end\n    if <touching color (#000008)?> then\n        change y by (1)\n    end\n    if <touching color (#000008)?> then\n        change y by (1)\n    end\n    if <touching color (#000008)?> then\n        change y by (1)\n    end\n    if <touching color (#000008)?> then\n        change y by (-4)\n        change x by ((x) * (-1))\n        if <key (up arrow v) pressed?> then\n            set [y v] to [15]\n            if <([abs v] of (x) ) = (x)> then\n                set [x v] to [-10]\n            else\n                set [x v] to [10]\n            end\n        else\n            set [x v] to [0]\n        end\n    end\n    change y by (y)\n    if <touching color (#000008)?> then\n        change y by ((y) - ((y) * (2)))\n        set [y v] to [0]\n    end\n    change y by (-1)\n    if <<key (up arrow v) pressed?> and <touching color (#000008)?>> then\n        set [y v] to [15]\n    end\n    change y by (1)\n    if <touching color (#ff0000)?> then\n        go to x: (-227) y: (41)\n    end\n    if <(x position) > [222]> then\n        next backdrop\n        go to x: (-230) y: (-141)\n    end\nend\n\n@Sprite2\n\n
Look at this~ https://scratch.mit.edu/projects/179963222/