Guys, i wonder how would the developers would feel about some developing a similar game with simil mechanics and gameplay (not exactly the same) and using their sprites as placeholder during the development...

Thing is I'm studying programming, and as a personal project and because  i absolutely love starsector, i started by my own a starsector-like game, from scratch, using only java and lwjgl3. Given i suck at drawing,  i imported some sprites from starsector as placeholders, with the intention to either pay someone to draw the sprites or draw them myself and improve them with ai in the future. I am not importing any code from the game nor have i even looked at. I'm taking it as a challenge to imagine and develop the mechanics on my own, and its gonna be quite different from starsector. First of all it's going to be fast pacing real time instead of tactical. 

So idk, should i stop importing anything and just do random shapes and free license texture imstead? I want to show it to people online and get feedback, but don't wanna get flamed for "stealing" from starsector, even though its just borrowing with no intention to keep them in the final game.

Starsector-like game