This game offers an excellent opportunity to enter the world of Trading card games (TCG).
A number of unique and interesting maps have already been created with each one containing three stages of development with obvious changes in art – which does not mean just a couple of extra brush strokes!
The plot and the gaming world can all be developed further to create a more immersive gameplay experience.
Things to be improved are more monetization triggers above and beyond promotions and events. Further development of the plot and storyline to include new locations, maps, new content, etc as well as expanding the games opportunity for strategic thinking such as a player being able to choose a target for attack. This would not significantly affect the game balance, but will add more involvement and immersion in the process.
This is a casual game but one that features high quality content and storyline which is a pre-requisite for any audience in such as niche area of the market.