Merge Elementals: Castle Defense — merge elemental tower defense
An army is marching toward your castle, and only a wall and a grid of elementals stand in their way. You can only buy level 1 fighters with gold. The only way to get stronger is by merging: two identical fighters of the same level combine into the next level. There aren’t many cells on the grid, so you have to plan who to merge ahead of time. The core merge mechanic will feel familiar from Castle Craft, but there you combine resources at your own pace, while here the horde is closing in on you.
Fire, water, and earth create wind, lava, and nature. From those come ice, energy, spirit, and sandstorm. There are twelve elements in total. Some burn enemies in an area, others slow the horde, and others hit a single target.
Merge only between waves
Once your setup is ready, you hit the start wave button. During battle, you can’t merge fighters. Elementals auto-target and shoot on their own, while you cast spells and make sure the wall holds. Every enemy you kill drops gold. Between waves, you upgrade your magic and pick three spells for battle. These include fireball, chain lightning, meteor shower, and dragon summon.
Each location has ten waves, and the last one is a boss fight. Beat it to unlock the next area: swamp, snowy peaks, tombs in the desert, mushroom forest, and more. Your army and gold carry over, so you don’t have to build your fighters again.