String Quartet No. 1 in C major

A string quartet that I completed on the 16th of June. It is in the classical style, inspired by the quartets of Mozart, Haydn, and Kozeluch (A very underrated composer who was more popular than Mozart during his life). 

While this isn't the style I normally look out for, this is pretty good.
The retardation at the end of your exposition in the first movement isn't as smooth as the other held tone resolutions. Speaking of, I think it's a little bit overused throughout the piece regardless of movement. Triadic shift is important but definitely can get trope-ish quite quickly. The last two movements felt rushed and incomplete, especially the last three tonic chords.
In the faster movements, I don't get a huge sense of energy from any of them. Early romantic and classical music knew it important to have some sort of rhythmic ostinato to drive energy, and I don't get a lot of it (maybe a bit in the last movement). It has a generally slow atmosphere over most of it. It doesn't have that classical excitement I'm used to hearing in Mozart or Mendelssohn. 
I can imagine it being played by live instruments though! Definitely would help it along. :)

This is nice. Some mild dissonances, spicy. Yes, it seems I am hearing "Mozart" or a young Beethoven. Most part of the first movement lacks of counterpoint. It's like a melodic instrument (violin) and background. I think this is the main handicap here, it happens the same in the second part. A string quartet must give the same importance to the 4 instruments. The opening theme in the third part is a bit naïve..., Schumann said that if you write a good beginning, the rest is almost done...

I. I like the opening theme. I echo the above though in stating that more importance should be given to all the members of the quartet -not just the 1st Violin. I also would go further to state this movement needs just a bit more contrast. The theme is interesting, but after a bit, it got boring. 

II. I can see the kernel here for an awesome second movement. However, I don't think this delivered fully. There seemed to be an over-reliance on the established accompaniment material. Again, this movement also suffers from a lack of contrast.

III. Where is the driving rhythm characteristic of an 18th century string quartet? This movement is almost as slow as the other two movements... why are the other instruments not joining in the melody? Give some of the running 8th and 16th notes to them, let them have some fun! And it ends so soon...

IV. A movement with a theme faster than the trio/scherzo? Say what??? Again, let the other three strings partake in the melody. They aren't just for providing a backdrop. This movement seems to have a lot more contrast then the previous three movements (and was very much welcome). This movement also was rushed to an ending and didn't deliver the final period of the entire string quartet.

All in all, I think you have an idea of melody construction and harmony. I'd like to see you do the following:

1. Expand your ideas more. From the start of the classical period to its final transition to the romantic period, composers expanded the roots and ventured off in dramatic ways - all within an extremely structured style that paid high regard to form. 

2. Look past the elementary usage of strings. The 2nd violin, viola, and cello are integral parts of a string quartet. They all, homogenously, create music that transcends the limitations of their construct. The cello, with the sound range of the human voice, is capable of extreme lyricism and storm alike. The viola, with its high nasal register and rich middle and lower range, serves multiple purposes and can even carry its own compared to its more popular counterparts. Explore how they can aide in transforming your thematic material and expand/develop it to its full potential.

and finally...

3. Individualize the forms you use. A form is a blueprint upon which you can present, develop, and finalize your ideas. Even though we have this blueprint -which is well known and taught, it does NOT mean that you have to adhere to it fully. And you should not adhere to it verbatim. One of the hallmarks of composition is that each individual can take the same tools and create something fresh and new. This was true of Haydn, Mozart, and Beethoven... just as much as it was true of Schoenberg, Webern, and Berg. The tools are the same, the outcome much different. Individualize your forms. Choose what areas you want to focus on -and have at it. Don't let the form overwhelm you -and don't be stuck by it. Mold it to fit the individual idea you decided would best suit that form.

I hope these points provide some guidance for you. You definitely have good material here. Let's see what YOU can do to make this better!

Thank you all for your replies! I'm writing three of them as my Opus 2, (I will post opus 1 shortly, which is three piano sonatas) and this was my first real string quartet, so I may have been a little too cautious. I agree that it's not a very energetic piece, and needs more counterpoint, which I will try do improve on in my next quartets, and I will definitely try to add more variety of form and instrumentation in all of the movements, a skill I hope to improve by experience and study of other composers's works. This was sort of a prototype quartet, so I will definitely individualize the genre for myself once I have the basics down.

Thanks again!