HTMLify

const trex = document.querySelector(".trex");
const obstacle = document.querySelector(".obstacle");
const intro = document.querySelector(".intro");
let counter = 0;
let keyCode;

function jump() {
    trex.classList.add("animate");
    setTimeout(() => {
        trex.classList.remove("animate");
    }, 500);
}

document.body.onkeyup = function(e) {
    if (e.keyCode == 32) {
        jump();
        obstacle.style.animation = "block 1s infinite linear";
        intro.style.display = "none";
        keyCode = e.keyCode;
    }
};

const checkDead = setInterval(function() {
    let trexPosition = parseInt(
        window.getComputedStyle(trex).getPropertyValue("bottom")
    );
    let obstacleLeft = parseInt(
        window.getComputedStyle(obstacle).getPropertyValue("left")
    );

    if (obstacleLeft < 50 && obstacleLeft > -50 && trexPosition <= 50) {
        obstacle.style.animation = "none";
        alert("Game Over. score: " + Math.floor(counter / 100));
        intro.style.display = "block";
        counter = 0;
        keyCode = "";
    } else {
        document.querySelector(".score").innerHTML = Math.floor(counter / 100);
        if (keyCode == 32) {
            counter++;
        }
    }
}, 10);