add some floor obstacle and make canvas move up as in tower, with constantly new obstacles appearing as platforms to jump up.: const canvas=document.getElementById("game-canvas");const context=canvas.getContext("2d");canvas.width=480;canvas.height=320;const GRAVITY=60;const ENEMY_RADIUS=10;const PLAYER_RADIUS=10;const TRACTION=.999;const OBSTACLE_COUNT=6;let playerX=50;let playerY=250;let isPlayerAlive=true;let enemyX=400;let enemyY=100;let enemySpeedX=0;let enemySpeedY=0;let enemyMultiplier=0;let playerSpeedX=0;let playerSpeedY=0;let playerIsOnGround=false;let lasers=[];let shootingTimer=0;let obstacles=[];const obstacleWidth=320;const obstacleHeight=5;function applyGravity(){if(!playerIsOnGround){playerSpeedY+=GRAVITY/60}}function applyTraction(){playerSpeedX*=TRACTION}function movePlayer(){if(!isPlayerAlive)return;playerX+=playerSpeedX;playerY+=playerSpeedY;if(playerX<0){playerX=0}if(playerX+PLAYER_RADIUS*2>canvas.width){playerX=canvas.width-PLAYER_RADIUS*2}context.fillStyle="pink";context.fillRect(playerX,playerY,PLAYER_RADIUS*2,PLAYER_RADIUS*2)}function moveEnemy(){if(!isPlayerAlive)return;const targetIndex=findNearestObstacle(playerX,playerY);const targetX=obstacles[targetIndex].x+obstacleWidth/2;const targetY=obstacles[targetIndex].y+obstacleHeight/2;const epsilon=.2;if(Math.abs(enemyX-targetX)>epsilon||Math.abs(enemyY-targetY)>epsilon){const angle=Math.atan2(targetY-enemyY,targetX-enemyX);enemySpeedX=Math.cos(angle)*2;enemySpeedY=Math.sin(angle)*2}else{enemySpeedX=0;enemySpeedY=0}enemyX+=enemySpeedX;enemyY+=enemySpeedY;if(shootingTimer<=0){shootLaser();shootingTimer=1}shootingTimer-=1e-4;context.fillStyle="cyan";context.fillRect(enemyX-ENEMY_RADIUS,enemyY-ENEMY_RADIUS,ENEMY_RADIUS*2,ENEMY_RADIUS*2)}function findNearestObstacle(x,y){let minIndex=0;let minDistance=Number.MAX_VALUE;for(let i=0;i<obstacles.length;i++){const dx=x-(obstacles[i].x+obstacleWidth/2);const dy=y-(obstacles[i].y+obstacleHeight/2);const distance=Math.sqrt(dx*dx+dy*dy);if(distance<minDistance){minDistance=distance;minIndex=i}}return minIndex}function isColliding(x,y,width,height){for(const obstacle of obstacles){if(x<obstacle.x+obstacle.width&&x+width>obstacle.x&&y<obstacle.y+obstacle.height&&y+height>obstacle.y){return true}}return false}function checkCollision(){if(isColliding(playerX,playerY,PLAYER_RADIUS*2,PLAYER_RADIUS*2)){if(playerSpeedY>0){playerY-=playerSpeedY;playerSpeedY=0;playerIsOnGround=true}else{playerY-=playerSpeedY;playerSpeedY=0}}else{playerIsOnGround=false}if(isColliding(enemyX-ENEMY_RADIUS,enemyY-ENEMY_RADIUS,ENEMY_RADIUS*2,ENEMY_RADIUS*2)){enemySpeedX=-enemySpeedX;enemySpeedY=-enemySpeedY;enemyX+=enemySpeedX;enemyY+=enemySpeedY}}function detectObstacleCollision(){for(const obstacle of obstacles){if(playerX+PLAYER_RADIUS*2>obstacle.x&&playerX<obstacle.x+obstacle.width&&playerY+PLAYER_RADIUS*2>obstacle.y&&playerY<obstacle.y+obstacle.height){if(playerX+PLAYER_RADIUS*2<obstacle.x+5){playerX=obstacle.x-PLAYER_RADIUS*2}else if(playerX>obstacle.x+obstacle.width-5){playerX=obstacle.x+obstacle.width}else{if(playerY+PLAYER_RADIUS*2<obstacle.y+5){playerY=obstacle.y-PLAYER_RADIUS*2;playerIsOnGround=true}if(playerY>obstacle.y+obstacle.height-5){playerY=obstacle.y+obstacle.height;playerSpeedY=0}}}if(enemyX+ENEMY_RADIUS*2>obstacle.x&&enemyX<obstacle.x+obstacle.width&&enemyY+ENEMY_RADIUS*2>obstacle.y&&enemyY<obstacle.y+obstacle.height){if(enemyX+ENEMY_RADIUS*2<obstacle.x+5){enemyX=obstacle.x-ENEMY_RADIUS*2}else if(enemyX>obstacle.x+obstacle.width-5){enemyX=obstacle.x+obstacle.width}else{if(enemyY+ENEMY_RADIUS*2<obstacle.y+5){enemyY=obstacle.y-ENEMY_RADIUS*2}else if(enemyY>obstacle.y+obstacle.height-5){enemyY=obstacle.y+obstacle.height;enemySpeedY=0}}}}}function shootLaser(){const laserSpeed=2;const angle=Math.atan2(playerY-enemyY,playerX-enemyX);const laserSpeedX=Math.cos(angle)*laserSpeed;const laserSpeedY=Math.sin(angle)*laserSpeed;lasers.push({x:enemyX+ENEMY_RADIUS,y:enemyY+ENEMY_RADIUS,speedX:laserSpeedX,speedY:laserSpeedY})}function moveLasers(){let playerHit=false;for(let i=0;i<lasers.length;i++){const laser=lasers[i];laser.x+=laser.speedX;laser.y+=laser.speedY;if(!playerHit&&laser.x>=playerX&&laser.x<=playerX+PLAYER_RADIUS*2&&laser.y>=playerY&&laser.y<=playerY+PLAYER_RADIUS*2){const randomColor="rgb("+Math.floor(Math.random()*256)+","+Math.floor(Math.random()*256)+","+Math.floor(Math.random()*256)+")";context.strokeStyle=randomColor;context.beginPath();context.moveTo(laser.x,laser.y);context.lineTo(laser.x+laser.speedX,laser.y+laser.speedY);context.lineWidth=3;context.stroke();playerHit=true;isPlayerAlive=false}if(laser.x<0||laser.x>canvas.width||laser.y<0||laser.y>canvas.height){lasers.splice(i,1);i}}if(playerHit){playerX=-100;playerY=-100}}function drawLasers(){context.fillStyle="red";for(const laser of lasers){context.beginPath();context.arc(laser.x,laser.y,5,0,Math.PI*2);context.fill()}}function drawObstacles(){context.fillStyle="yellow";for(const obstacle of obstacles){context.fillRect(obstacle.x,obstacle.y,obstacle.width,obstacle.height)}}function createObstacles(){for(let i=0;i<OBSTACLE_COUNT;i++){const obstacleX=Math.random()*(canvas.width-obstacleWidth);const obstacleY=Math.random()*(canvas.height-obstacleHeight);obstacles.push({x:obstacleX,y:obstacleY,width:obstacleWidth,height:obstacleHeight})}}function checkEnemyDeath(){if(isPlayerAlive&&playerSpeedY>=0&&playerY+PLAYER_RADIUS*2>enemyY-ENEMY_RADIUS&&playerX+PLAYER_RADIUS*2>enemyX-ENEMY_RADIUS&&playerX<enemyX+ENEMY_RADIUS){playerSpeedY=-20;playerIsOnGround=false;enemyY=-100;enemyX=-100;setTimeout(spawnNewEnemy,1e3);enemyMultiplier++}}function spawnNewEnemy(){enemyX=Math.random()*(canvas.width-ENEMY_RADIUS*2);enemyY=Math.random()*(canvas.height-ENEMY_RADIUS*2);for(let i=0;i<enemyMultiplier-1;i++){shootLaser()}}function draw(){context.fillStyle="black";context.fillRect(0,0,canvas.width,canvas.height);applyGravity();applyTraction();movePlayer();moveEnemy();moveLasers();checkCollision();drawLasers();drawObstacles();checkEnemyDeath();detectObstacleCollision();requestAnimationFrame(draw)}createObstacles();draw();document.addEventListener("keydown",event=>{if(event.code==="KeyA"){playerSpeedX=-5}if(event.code==="KeyD"){playerSpeedX=5}if(event.code==="KeyW"&&playerIsOnGround){playerSpeedY=-20;playerIsOnGround=false}});document.addEventListener("keyup",event=>{if(event.code==="KeyA"||event.code==="KeyD"){playerSpeedX=0}});