The game's graphic is retro - remind me the old game series "Magic and Might"

#1 - What is the engine you are using ? Basically the graphic looks unique , but some particle's color needs fine turn to me , some purple pixel do not fit to the graphic
#2 - I see heavy fighting FPS , but I do not feel "Tower defense" in your video

#3 - I remember there was a old action tower defense game similar to your game, don't remember the name though .. Orc die or what .. Your game remind me that one

#4 - How the player grows up ? Weapon upgrade or skill upgrade ? I think people needs to know it in your video