Research is key to making a good game as it allow you to find out what works well with you idea and helps you develop them more What I plan on Research, what art style to do, What type of game (action etc.),Roman mythology,
Art styles / 3D or 2D-
photorealism means artist studies a photograph and then attempts to reproduce the image as realistically as possible in another medium. Eg Games. Games that use this Project Cars,Hitman (2016),Far Cry 5 ,GTA 5 just to list a few of them.
Cel Shading or toon shading is a type of non-photorealistic rendering designed to make
3-D computer graphics appear to be flat by using less shading color instead of a shade gradient or tints and shades. Game that use this are The Legend Of Zelda: The Wind Waker,Ni No Kuni,Okami,walking Dead,Borderlands.
2D Pixel Art The art style which refuses to die. Even though pixel art was originally created out of necessity due to the limitations of old games consoles, many modern indie designers have co-opted the visual style. And here are some good examples Stardew Valley,Terraria,Shovel Knight,Hyper Light Drifter.
These are the 3 styles I like the most to decide I have made a survey to help me make my game and these are the results.
from these results it is clear that 2D pixel art is the most popular doubling the other 2.
What Works Well with role playing Games-
“when talking with one of my teachers they informed me that making a turn based strategy game in the time I have would be very hard to do. So they suggested I tried to Find a tutorial before I invested too much in to my game idea (I have had a look online and most tutorials that I have found I think they are too time consuming) So sadly I couldn’t find one that would work well with the time I have to make it”
My first game idea would be a turn-based strategy but looking in to this I found out it would take to much time make. So now I have decided to look up some games and then add it to a survey and see what is the most popular.
once again from these results it is clear that action games is the most popular doubling the other 2.
Now I know it is going to be a top down role playing action game I’m going to look up good examples, These are some of them, Diablo 1,2,3 also Grim Dawn,Torchlight 2 And then there is Titan Quest. 
Enemy/Npc Ideas-
As my game will be based in the roman empire times. I decided to look up some Roman mythology, Roman mythology is the history, myths and legends. In Roman Mythology they talk about gods, goddesses, heroes & supernatural creatures. I thought some of these would make good enemies in my game.
1.In Mythology the centaur was a creature, part human and part horse. he would be good for my game as Npc that help you fight or maybe fight you as you made a choose that has upset them and now they are your enemies.
2.The Colchian Dragon guarded the Golden Fleece in Mythology. Think this could be a good side quest as if you are finding it hard with the many story you could head out and go get the Golden Fleece (Golden Fleece has magic healing abilities).
3.The Graeae were three gray witches in Mythology who possessed on one eye between them, consulted by the hero Perseus. These Would be good for Npc as they chaotic and they would try leed you down a evil path and trick you in to do bad thing. (My seem good but are not)
4.The Chimera was a fire breathing beast that was part lion, part goat, and had a snake-headed.
5.In Mythology the Hydra was the many-headed sea monster which when one of its heads was cut off grew two more.
6.Ladon In Mythology Ladon was the dragon which guarded the golden apples in the Garden of the Hesperides
7.Medusa Medusa was one of the Gorgons in Mythology, a winged monster who had live snakes for hair who could turn men to stone, slain by the hero Perseus
8.Orthrus was the two-headed dog which guarded the Cattle of Geryon in Mythology
These are just some idea I will not be adding all these. I have not gone in too to much detail as 4-8 Will just be good ideas for side quest or boss battles or just enemies.
Game Design 