need to make properre entitities spawning function, so they can multiply by numbers after each entity is passing away through left side of canvas and disappears. need to make some factor on which the entities multiply by time as well. so, for example, one entitty is left canvas through left side and two entities are spawned from the right side, but need to make some factor on which it decides if one or two entities be spawned in each iteration, so they not rapidly spawn in swarms of entities on the next iteration in progression. so, the more time passed, the more chance that there will be more entities going from the right side to the left and shoting their physical projectiles to player's square while player trying to jump on platforms.: 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}}}class Projectile{constructor(x,y,vx,vy){this.x=x;this.y=y;this.vx=vx;this.vy=vy;this.radius=10;this.color="red"}update(){this.x+=this.vx;this.y+=this.vy}draw(ctx){ctx.beginPath();ctx.arc(this.x,this.y,this.radius,0,2*Math.PI);ctx.fillStyle=this.color;ctx.fill()}}class Entity{constructor(){this.x=canvas.width;this.y=Math.random()*canvas.height;this.vx=-1-Math.random()*3;this.vy=-2+Math.random()*4;this.projectiles=[];this.color="blue"}update(){this.x+=this.vx;this.y+=this.vy;if(Math.random()<.01){this.projectiles.push(new Projectile(this.x,this.y,-2-Math.random()*6,-2+Math.random()*8))}for(let i=0;i<this.projectiles.length;i++){this.projectiles[i].update();if(this.projectiles[i].x<0||this.projectiles[i].y<0||this.projectiles[i].x>canvas.width||this.projectiles[i].y>canvas.height){this.projectiles.splice(i,1);i}}}draw(ctx){ctx.fillStyle=this.color;ctx.fillRect(this.x,this.y,20,20);for(let i=0;i<this.projectiles.length;i++){this.projectiles[i].draw(ctx)}}}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=1;this.entities=[];this.entitySpawnRate=.1;this.entitySpawnTimer=10;this.keys={};this.platforms.push(new Platform(0,canvas.height-50,50,10));for(let i=0;i<10;i++){this.createRandomPlatform()}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}for(let i=0;i<this.entities.length;i++){if(this.entities[i]){this.entities[i].update();if(this.entities[i].x<0){this.entities.splice(i,1);i}else{for(let j=0;j<this.entities[i].projectiles.length;j++){if(this.entities[i].projectiles[j].x>this.player.x&&this.entities[i].projectiles[j].x<this.player.x+this.player.w&&this.entities[i].projectiles[j].y>this.player.y&&this.entities[i].projectiles[j].y<this.player.y+this.player.h){this.player.vy-=20;this.player.jumping=true;this.entities[i].projectiles.splice(j,1);j}}this.entities[i].draw(this.ctx)}}}this.player.x-=this.scrollSpeed;if(this.platforms[this.platforms.length-1].x<this.canvas.width-200){this.createRandomPlatform()}this.entitySpawnTimer++;if(this.entitySpawnTimer>=60/this.entitySpawnRate){this.entitySpawnTimer=0;this.entities.push(new Entity);this.entitySpawnRate+=.1}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)}for(let i=0;i<this.entities.length;i++){this.entities[i].draw(this.ctx)}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);