If I make a game like those of JSK Studio, will it be considered copyright infringement?

[Karlken]

Firstly in case you don't know, here are JSK's games.
I really like this format and want to make a similar game with better graphics, but I don't know if doing so will lead to any problems. Like, if the gameplay has up to 90% similarity? I know there are billions of similar RPGM games out there, but this case may be different. And I also plan to sell it on DLsite if things go well later.
Need advice from you guys. Thank you.

 

[FromOtherSpace]

Hi,

Why it could be different?

Have this company any unique gameplay which are protected by patent?

I don't know these games. For what I see, its some bars which fill when you do things, things you can do are show on screen and you click on it to play. Nothing unique. Nothing protected by law. Only an interface. Don't steal their graphics, nor their stories/characters, and anything will be fine.