One of the most important part of a game is making the feel of the game and art can be a huge part in that.
I am currently making an anime-ish cartoonish kinda game and I am wondering how I can make it really look the part. As how anime is it should be kinda of realistic but still with that cartoonish feel.
So how can I go about doing this?
So far I’ve customized the trees and lighting, Im also can hand-draw some VFX and weapons details
Depends on what kind of game you want to make. Personally, I like all my games mostly to have that cartoony and more laid-back feel. What I do is make the most of color usage and play with the lighting. The lighting in certain spots can make a HUGE difference! Maybe try adding some upbeat music or playful sounds!
Hope this helps! 
There are many great stylized textures in substance painter, use that for your models, there are tutorials on anime trees, and change the terrain texture to custom. Adddhighlights on important things like the player (max 31)