*{
  padding: 0;
  margin: 0;
}
#game{
  width: 400px;
  height: 500px;
  background-color: white;
  border: 1px solid black;
  margin: auto;
  overflow: hidden;
  
}
#block{
  width: 50px;
  height: 500px;
  background-color: black;
  position: relative;
  left: 400px;
  animation: block 2s infinite linear;
}
@keyframes block{
  0%{left: 400px;}
  100%{left: -50px;}
}
#hole{
  width: 50px;
  height: 150px;
  background-color: white;
  position: relative;
  left: 400px;
  top: -500px;
  animation: block 2s infinite linear;
}
#character{
  width: 20px;
  height: 20px;
  background-color: red;
  position: absolute;
  top: 100px;
  border-radius: 50%;
}