MSFS一前些日以前子发行了。

The subject does not correct
I do some work. MSFS is a game.
In English, MSFS had been published -> that what you want to say. But you translate in Chinese. That doesn't make sense. It is hard to explain. grammar issues.
By grammar, in English, thought grammar we could know somebody/sth was been published. The subject was been public.
But in Chinese, MSFS published something. that what you wrote in Chinese. Sorry, it is very hard to explain.
have been polished ---> [MSFS] 已经（被）发布了 ---> what you want to say
polished ---> [MSFS] 发布了 --->what you wrote ---> MSFS is game can not polish sth.

you can write " MIC published MSFS a few days ago" ---> 微软前些日子发行了MSFS" ---- this one will be the best


Or ” MSFS was been published a few days ago " MSFS 前些日子被发行了“

by the way, 了 in Chinese, it can show people the past perfect tense.

我不没有买它，但是使我怀旧一点。

In here， 没有 will be better than 不
the next part I don't get it

我玩过FSX，飞行模拟器被Microsoft也作了。

I don't get it

FSX是在2006年发行了，因此我开始玩的时候，不好的。

don't relate
you said the FSX was been published in 2006. I don't want know why you add relate word in here ( 因此？）
the problem is here is the linking word. 因此 = because ... so
in here don't make sense. it sounds like because the game was been published in 2006, so you don't like it.

虽然这样，但是我还很喜欢它。因为是我玩过的第一的飞行模拟器。

我很想试试MSFS，但是太贵了，因此要等。

you add an explanation of why you need to wait. Here, it sounds like you like the game but you don't have enough money, then you have to wait. why you need to wait ?????
I will not make the correction with this sentence. I think you can rewrite it better.

MSFS一些日以前于前几日发行。

我不买它虽然没有买，但是它使我怀旧一点想到了从前。

我之前玩过FSX，飞行模拟器被Microsoft也作了。

我没有看懂这句话后半部分的意思。

FSX在2006年就发行了，因此我开始玩的时候，那时候的体验并不好的。

虽然这样如此，但是我还是很喜欢，因为它是我玩过的第一的揍飞行模拟器。

虽然这样也不算错。

我很想试试MSFS但是，但它现在太贵了，因此要我想再等等。