I'm glad the dev has decided to develop this great game further, since I used to play it for endless of hours. Although as far as I know, there is no more serious plans beyond adding of new hybrids, which is a shame since the potential is still huge.
Unfortunately the game is still no perfect as it can be quite repetitive, especially if we start a new game and go through the whole grindy battle again.
The problem starts with the fact that once you create an unbeatable team, you've practically won, since (unless you throw a coin in the well) those random mobs won't be able to stop you. From then on, we only have to do is slapping all the enemies on the map until we reach a boss. But every boss is also just a passive enemy who waits for us until we beat them. Maybe they should occasionally send a stronger than average team against our city, which is capable of a more serious blow compared to the average mobs.
The game definitely should force the player to hold several strong army at once, and somehow the developer should solve that the enemy can attack even if we are outside the city with our FMC.
My other idea is that as we progress in the game, we could later own several new cities at the same time in different places on the map, with different styles of buildings and possibilities, which could even be taken over by the enemy.
Overall, I think the game should put a little more emphasis on the management part too, and for the tower defense combat, instead of just blindly wandering around the map fighting with random enemies.