2581 is a free trivia game for Android developed by RucKyGAMES. The objective of the game is to solve a riddle by figuring out the correct numeric code. The game consists of a series of nine riddles, and each riddle presents a set of numbers with a corresponding hint. The player must use the hint to deduce the correct code and progress to the next level.

The game's interface is simple and easy to navigate. The player is presented with a keypad to enter their answer and a button to submit it. If the answer is correct, the player moves on to the next level. If the answer is incorrect, the player must try again. The game's difficulty increases with each level, and the final riddle is the hardest of them all. Players can challenge their friends and family to see who can solve the riddles the fastest.