Hi, I’m no an expert, I still learning from experts here, so I really like your job you did a good job, but I guess there are some instruments that you have to change or upgrade also I guess you have to work more on mixing and mastering, other advice is to generate a wave file and check it’s loudness penalty here it can help :
Loudness Penalty: Analyzer
Also, check other experienced authors comments in the forum it can help, there are many authors having amazing skills like the comment of ’ Daydreamz-Studios’ here in this post, Damn that guy has 100 ears lol :
Good luck