エイリアンのたまご - Idle Battle RPG Game App is a free-to-play game for iPhone developed by PAON DP Inc. It is a space adventure game with a total of over 1400 unique and stylish aliens available. The game revolves around breeding and raising your own unique alien and taking them on an adventure through space.

You can customize your alien's stats by feeding them and breeding them with other players' aliens. The game also features an auto-battle function and a 2x speed feature, making it easy to play and clear quests. You can also form a team with up to 15 other players to take on powerful bosses and engage in team battles. The game offers a monthly subscription service called "Eritama Premium" for $4.99 a month, which offers various benefits and perks.