Merge Archer Defense combines the merge mechanic with castle defence: you place stickman archers, combine identical ones into stronger versions, and hold the walls against an advancing army.
Because merging costs you a unit, the decision is always whether to hold the line with numbers or gamble a gap on making one archer much better.
Two identical archers combine into a stronger single unit — so you trade quantity for quality, which is the game's central decision.
Between waves. Merging during an assault leaves you a defender short at the moment you need the numbers.
Yes — drag to merge and swipe to shoot. Nothing to install.