* {
    padding: 0;
    margin: 0;
    overflow-x: hidden;
}
.game {
    width: 500px;
    height: 200px;
    border: 1px solid black;
    margin: auto;
}
#character {
    width: 20px;
    height: 50px;
    background-color: red;
    position: relative;
    top: 150px;
}
.animate {
    animation: jump 0.3s linear;
}
@keyframes jump {
    0% {
        top: 150px
    }
    30% {
        top: 100px
    }
    70% {
        top: 100px
    }
    100% {
        top: 150px
    }
}
#block{
    background-color: blue;
    width: 20px;
    height: 20px;
    position: relative;
    top: 130px;
    left: 500px;
    animation: block 1s infinite linear;
}
@keyframes block{
    0%{
        left: 500px
    }
    100%{
        left: -20px
    }
}
p {
    text-align: center;
}