Eternum EX is a retro-style platformer game developed by Radin Games for Nintendo Switch. The game is heavily inspired by classic arcade cabinet games from the 80s, such as Bomb Jack, Ghosts'n Goblins, Baluba-louk no Densetsu, and Psychic 5. In this game, you play as Sir Arthur, an old knight who embarks on a journey to the evil subterranean kingdom of Samarnath in search of treasures and five magical orbs that provide eternal youth.

The game has a progressive difficulty curve, divided into "worlds" of five levels each. Eternum EX is easy to play but hard to master, with simple core gameplay mechanics and precise controls that make it perfect for hardcore retro gamers. The game also has a memorable soundtrack, 16-bit aesthetics, and plenty of different enemies to defeat. There are 25 levels in total, including special levels with final bosses, and secrets bonuses on each level. Finally, the game also features a worldwide "High Score" leaderboard.