To run the desktop samples can use the Gradle run task.
For vtm-playground can change the main class in build.gradle and pass args:
./gradlew :vtm-playground:run -Pargs=/path/to/theme,/path/to/hgt,/path/to/map1,/path/to/map2
To create a standalone executable jar, change the main class in build gradle and run:
./gradlew :vtm-playground:fatJar
The jar file can be found in build/libs folder. Depending on the main class, pass args on execution via command line:
java -jar vtm-playground-master-SNAPSHOT-jar-with-dependencies.jar /path/to/theme /path/to/hgt /path/to/map1 /path/to/map2
The theme file and SRTM hgt folder are optional arguments.
To change the libGDX backend can replace the dependency: vtm-desktop-lwjgl or vtm-desktop-lwjgl3.