Border Wars: WW2 Army Games may look like a Minecraft version of Battle Cats, but trust me, this game is harder than expected. The game is indeed challenging, though it won't feel like so with the first few missions. Honestly, the first few missions were a breeze... until I hit a wall in the later missions and it suddenly felt a whole lot harder.
Like I said, it's basically Battle Cats with a Minecraft-like look. Players spawn soldiers with money until they destroy the enemy base. Money management is important, and knowing which units to spawn is key to victory. Blindly choosing which soldiers to send out can be detremental, so planning them out while paying attention to your cashflow is certainly a must.