Playability:I found this game pretty addicting getting your soldiers where you need them and having a strategy too defend.
Balance:I beat this on normal with 4% of my troops gone you need to make it harder.
Creativity: With nothing standing out its just a regular invasion map.
Map Design:It was ok but you you need to use more shrubs and change the ground so most of it isnt just plain land, but overall it was ok.
Story: The story was way to short and if youre going to do a series especially a series you should have something longer you should have something stating 1)why you are fighting 2)Some background on your character or people.
3)what you seek in the future, and thats pretty much it a lot of people write a lot more though.
I would suggest you play other peoples scenarios first before you make anymore just for ideas and for fun you should rate them once you are done or at least leave a small note.
Im starting a series too my first one is The Betrayal part1 you may want to play that one for some ideas.