Blob Jump is a side scrolling game you can play in your browsers URL bar. Add as a bookmarklet to play on any page.

blob-jump.js

(function(){
  let running = false;
  const levelLength = 42;
  const startLevel = new Array(levelLength + 1).join('_');
  let level = startLevel;
  const hurdle = '‗';
  const air = '■';
  let jump = false;
  let frame = 0;
  let score = 0;
  let i;

  function tick(){
    if(!running){
      if(i){
        clearInterval(i);
        i = null;
      }
      return;
    }
    const h = nextFrame();
    window.location.hash = h;
  }


  function nextFrame(){
    if(random(1,3) === 1 && level.slice(-1 * frames.length).indexOf(hurdle) === -1){
      level += hurdle;
    }else{
      level += '_';
    }
    level = level.substr(1);
    const c = character();
    if(c !== air && level[0] === hurdle){
      level = startLevel
      running = false;
      frame = 0;
      jump = false;
      const msg = formatMsg('[SCORE:_' + score + ']_(p:restart)');
      score = 0;
      return msg;
    }else if(level[0] === hurdle){
      score += 1;
    }
    return '_' + c + level;
  }

  function random(min, max) {
    return Math.round(Math.random() * (max - min) + min);
  }

  const frames = [
    '▅',
    '▅',
    '▄',
    '▃',
    '▁',
    '▁',
    '▃',
    '▄',
    '▆',
    '■',
    '■',
    '■',
    '■',
    '▅',
    '▄',
    '▃',
    '▁',
    '▃',
    '▃',
    '▄',
    '▅'
  ];

  function character(){
    if(jump){
      frame++;
      if(frame >= frames.length){
        frame = 0;
        jump = false;
      }
    }
    return frames[frame];
  }

  function start(){
    i = setInterval(tick, 1000 / 12);
  }

  function formatMsg(msg){
    const padding = startLevel.substr(levelLength / 2 + Math.floor(msg.length / 2));
    return padding + msg + padding;
  }

  window.addEventListener('keydown', evt => {
    if(evt.key === 'p'){
      evt.preventDefault();
      running = !running;
      if(running){
        start();
      }else{
        window.location.hash = formatMsg('[PAUSED]_(p:resume)');
      }
    }else if(evt.key === ' '){
      jump = true;
      evt.preventDefault();
    }
  });

  window.location.hash = formatMsg('[BLOB_JUMP!]_(p:play/pause)_(space:jump)');
})();

javascript:!function(){let n=!1;const t=42,e=new Array(t+1).join("");let o=e;const r="‗",a="■";let s,i=!1,l=0,u=0;function c(){if(!n)return void(s&&(clearInterval(s),s=null));const t=function(){1===(t=1,s=3,Math.round(Math.random()(s-t)+t))&&-1===o.slice(-1h.length).indexOf(r)?o+=r:o+="";var t,s;o=o.substr(1);const c=function(){i&&++l>=h.length&&(l=0,i=!1);return h[l]}();if(c!==a&&o[0]===r){o=e,n=!1,l=0,i=!1;const t=d("[SCORE:"+u+"](p:restart)");return u=0,t}o[0]===r&&(u+=1);return""+c+o}();window.location.hash=t}const h=["▅","▅","▄","▃","▁","▁","▃","▄","▆","■","■","■","■","▅","▄","▃","▁","▃","▃","▄","▅"];function d(n){const o=e.substr(t/2+Math.floor(n.length/2));return o+n+o}window.addEventListener("keydown",t=>{"p"===t.key?(t.preventDefault(),(n=!n)?s=setInterval(c,1e3/12):window.location.hash=d("[PAUSED](p:resume)")):" "===t.key&&(i=!0,t.preventDefault())}),window.location.hash=d("[BLOB_JUMP!](p:play/pause)(space:jump)")}();