WHAT DA FUX DATS f**kKIN EPIC
Andros your srsly making that whole shit by yourself?
Actually the engine is the base for all the polygons and physics.
I used to work with shit like that, also tested a couple of 'selfmade' games by some friends back in the schooldays.
Although those games were looking more shitty

You will be surprised afterwards how much computer performance it requires.
For example:
You copied the grass 1000x times which will cost a lot of working memory. At least it looks like it.
Depending on what kind of physics engine you use, you might wanna have sprites for grass for example, it'll reduce performance requirements alot.
I know it takes a lot of time and even more patience, I am amazed you're planning such a big game on your own.
Good luck with it man.