I will start off by saying that this is a serious question that affects my personal project, but it is more of a broader question that is meant to be discussed for every project in general.
So this is an issue of people who, like me, can't draw or create pixel art, and are stuck using RTP and third-party assets. In that regard, I think it is useful to separate the question in 2 parts: one for the tilesets, and another for the characters/battlers.
Question 1: For the tilesets, is having different art style alright for you?
So let's start off with tilesets. What do you think of using different tilesets from different artist, mixing it up with the RTP? Now some third party assets are very close to the RTP style, and others are even edits of RTP. I suppose that would easier to accept? Now how about a tileset with a more noticeable art style difference? How about that?
Question 2: For the characters, is having different art style alright for you?
This is where it gets a bit more complicated. Unlike tilesets, it is relatively easier to get a friend to draw some characters for you, or even commission someone to do it. However, it is unlikely that you will get images for every character in your game, every npcs, etc. So many people would end up with custom art for their party members, but not for secondary characters and npcs. So here are some sub-questions:
- 2.1: Does it bother you to see different art styles for the faces in dialogues? (custom art for the main characters, and RTP for NPCs for example)
- 2.2: If it does bother you, would you prefer that the dev remove faces altogether from dialogues? Or would you prefer to have a RTP face version of the main characters, even if it clashes with the full body character art style?
Now for battlers. They are a big part of many games, since the battle is usually a pretty important aspect. Some third-party assets have style very close, or even similar to the default RTP, so let's not take those into account.
- 2.3: Do you mind having some battlers with different art style mixed with default RTP style battlers?
- 2.4: If all the enemies have a different art style than the actor battlers, will it still bother you? (the art style is consistent between every enemies, just not with actors)