build.sbt

name := "kata01"

version := "0.1"

scalaVersion := "2.13.5"

libraryDependencies ++= Seq (
  "com.badlogicgames.gdx" % "gdx-backend-lwjgl" % "1.9.12",
  "com.badlogicgames.gdx" % "gdx-platform" % "1.9.12" classifier "natives-desktop",
)

DesktopLauncher.scala

import com.badlogic.gdx.backends.lwjgl.{LwjglApplication, LwjglApplicationConfiguration}

object DesktopLauncher extends App {
  val config = new LwjglApplicationConfiguration
  new LwjglApplication(new MyGdxGame, config)
}

MyGdxGame.scala

import com.badlogic.gdx.graphics.g2d.SpriteBatch
import com.badlogic.gdx.graphics.{GL20, Texture}
import com.badlogic.gdx.{ApplicationAdapter, Gdx}

class MyGdxGame extends ApplicationAdapter {
  lazy val batch = new SpriteBatch
  lazy val img = new Texture("assets/hello.png")

  override def create(): Unit = {}

  override def render(): Unit = {
    Gdx.gl.glClearColor(1, 0, 0, 1)
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
    batch.begin()
    batch.draw(img, 0, 0)
    batch.end()
  }

  override def clone(): Unit = {
    img.dispose()
    batch.dispose()
  }
}