Not to contradict Jason's comments but I feel a 13 minute demo reel or even 10 minutes is actually way too long. The conventional wisdom I've always heard is keep a demo reel under 4 minutes and some folks even advocate 2 minutes. I've actually watched several audio directors sample demo reels and it was eye opening. Most of the ones I've observed "dropped the needle" in random spots throughout the demo and would listen for about 5-10 seconds each time. It was like an extreme case of ADHD. They might only drop in at 3-4 spots over your whole demo reel to get a taste of what you do. If it's up to par and interests them, they'll listen more later. If not, they move on. In some cases the amount of time I've seen a demo reel get with an audio director (or manager) can be as short as 10 seconds total! So you really need to make a lasting impression right out of the gate!
I do agree 100% with Jason on the redundancy point. Try and think of ways to make it easier and faster for a game developer to quickly identify if you're the type of composer he or she needs. The quality of music and production, overall, is there!
The important thing to remember about demo reels are there only an introduction to (hopefully) a longer conversation. In other words don't give the client too much but a concise intro which leaves them wanting to know much more about you and your work.
Content critique - the retro cue at 6:11 is drastically lower in volume and, to be honest, isn't really selling you well as a retro-styled composer. I'd consider replacing that with something more substancial that really makes you shine. Retro style music actually requires more production pizzaz than more realistic samples which can do much of the work for you. This retro cue felt a bit more unfinished to my ears than the rest of your music which really did a good job showing your talent and efforts.
Closing thought: I left your demo reel feeling like you were mainly an orchestral composer who dabbles in some other styles, mostly synth stuff including some retro. Your focus though, appears to be orchestral. Mostly your style was dramatic and epic. This is mainly to get you to think about your demo and your marketing target(s). If you feel you're something else, which I haven't mentioned then perhaps your demo reel isn't showing that enough (or well enough) to give me that impression.
Good music! Just tweak how you're presenting it to make it easier and faster for potential clients to say "oh yeah, THIS is the guy I want to use!"