This looks like a properly fleshed-out little game, and no microtransactions, ads, or tracking to be found (the game doesn’t even request internet access!)

Build towers and facilities as you expand your land and clear enemy waves

Lay the path that the waves of enemies advance in a variety of ways. Read the towers/facilities card description carefully and place it in the appropriate location. Flag-shaped resources allow you to build towers/facilities on empty land or water. Bomb-shaped resources allow you to build new towers/facilities where there are already existing towers/buildings. (The road is not broken) A powerful boss enemy appears every 5 rounds.

There are 6 difficulty levels (easy, normal, bonus1, hard, bonus2, challenge). In hard difficulty, the enemy wave direction is 2 directions and in challenge difficulty, the enemy wave direction is 4 directions. Collect gems to clear higher difficulties through bonus difficulties. Use gems on the start screen to buy level 2 towers/facilities or upgrade resources to take on higher difficulties.