Merge Defense 3D is a tower defense game that combines numbers and strategy. The game is easy to play but challenging, making it a great way to train your brain. The objective of the game is to place defenders on the board to shoot enemies and merge two defenders with the same numbers to upgrade their power. The game also features power-ups and tools like freeze, bluster, and time killer that can be used to collect gems and keys. The game is completely free and has no time limit, making it a great way to pass the time.<br/><br/>The gameplay of Merge Defense 3D is addictive and interesting. The game requires players to think ahead by counting and making predictions. The game also requires players to merge defenders to become stronger. The game is a mix of tower defense, shooter, and merger games, making it a unique and fun experience. The game is designed to be challenging but not too difficult, making it suitable for players of all ages.<br/><br/>The game features a puzzle game that trains your brain. The game has no time limit, so players can play at their own pace without any pressure. The game is completely free, so players can enjoy the game without any cost. Merge Defense 3D is a great way to pass the time and train your brain. The game is a must-try for anyone who loves tower defense games and wants to try something new.