now need some random entity to appear from the right side to the left side with some chaotic movements and shot some projectiles at the player that pushing and affecting physics of the player square , and then this entities simply disappear from the left side. need to multiply this entities spawn rate and amount in dependence of player progression time.  make it endlessly spawn from the right side by chaotically moving in progression with platforms to the left side and then they should simply disappear by reaching the left side of canvas. entities need to multiply in count of enities spawned with player progression or just some basic timer, and enities should shot some projectiles which affects player square physics a little. also, need to make basic projeciles to display. output concise code: class Platform{constructor(x,y,w,h){this.x=x;this.y=y;this.w=w;this.h=h}collidesWith(obj){if(obj.y+obj.h<=this.y)return false;if(obj.y>=this.y+this.h)return false;if(obj.x+obj.w<=this.x)return false;if(obj.x>=this.x+this.w)return false;const objAbove=obj.y+obj.h-obj.vy<=this.y;const objBelow=obj.y-obj.vy>=this.y+this.h;const objLeft=obj.x+obj.w-obj.vx<=this.x;const objRight=obj.x-obj.vx>=this.x+this.w;if(obj.vy>0&&objAbove&&!objBelow){obj.y=this.y-obj.h;obj.vy=0;obj.jumping=false;return true}if(obj.vy<0&&!objAbove&&objBelow){obj.y=this.y+this.h;obj.vy=0;return true}if(obj.vx<0&&objRight){obj.x=this.x+this.w;obj.vx=0;return true}if(obj.vx>0&&objLeft){obj.x=this.x-obj.w;obj.vx=0;return true}return false}}class Player{constructor(x,y,w,h){this.x=x;this.y=y;this.w=w;this.h=h;this.vx=0;this.vy=0;this.jumping=false}move(keys){const friction=.9;const gravity=1;if(keys[87]&&!this.jumping){this.vy-=20;this.jumping=true}if(keys[68]){this.vx+=5}if(keys[65]){this.vx-=5}this.vx*=friction;this.vy+=gravity;this.x+=this.vx;this.y+=this.vy;if(this.x<0){this.x=0}if(this.y<0){this.y=0}if(this.x+this.w>canvas.width){this.x=canvas.width-this.w;this.vx=0}if(this.y+this.h>canvas.height){this.y=canvas.height-this.h;this.vy=0;this.jumping=false}}}let canvas=document.createElement("canvas");canvas.width=window.innerWidth;canvas.height=window.innerHeight;document.body.appendChild(canvas);class Game{constructor(canvas){this.canvas=canvas;this.ctx=canvas.getContext("2d");this.platforms=[];this.player=new Player(100,100,50,50);this.scrollSpeed=4;this.platforms.push(new Platform(0,canvas.height-50,50,10));for(let i=0;i<10;i++){this.createRandomPlatform()}this.keys={};document.addEventListener("keydown",evt=>{this.keys[evt.keyCode]=true});document.addEventListener("keyup",evt=>{delete this.keys[evt.keyCode]});requestAnimationFrame(this.update.bind(this))}createRandomPlatform(){const x=this.canvas.width;const y=Math.random()*this.canvas.height;const w=50+Math.random()*150;const h=10;this.platforms.push(new Platform(x,y,w,h))}update(){this.player.move(this.keys);for(let i=0;i<this.platforms.length;i++){this.platforms[i].collidesWith(this.player);this.platforms[i].x-=this.scrollSpeed}this.player.x-=this.scrollSpeed;if(this.platforms[this.platforms.length-1].x<this.canvas.width-200){this.createRandomPlatform()}this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height);for(let i=0;i<this.platforms.length;i++){let p=this.platforms[i];this.ctx.fillRect(p.x,p.y,p.w,p.h)}this.ctx.fillRect(this.player.x,this.player.y,this.player.w,this.player.h);requestAnimationFrame(this.update.bind(this))}}let game=new Game(canvas);