There's lots of good advice here already, so I'll give you the "real talk" shtuff you asked for about your work.
I'm going to be fairly critical, but I'm just trying to help, so please don't hate me.
I'm gonna go from what I think is your worst work to the best.
Skyrim level - If I were looking for a level designer, this doesn't show me that you can do it. If you had a better lit walk-through of the level with the enemies being non-hostile or something so that way I could see the lay-out and design, then maybe it would help. Also, its in an existing games level maker, using all pre-made content, so it won't be considered as strong of a portfolio piece as original content.
Maya models - There are a lot of very skilled 3D modelers, riggers, and animators out there. That being said, I don't think model making is your strong suit. If it is a direction that you want to pursue, then I would try to find an area of 3D content that you want to focus on. Like if you want to animate characters, I would start with simple skeletal rigs and animate out scenes. If you want to do character modeling, start with lower poly characters to learn good topography and patch modeling and practice. If it's just a side note, then I wouldn't nesicarily have this in the portfolio.
The Skyrim level and the Maya models are your weakest because they aren't what you'd expect to see from someone who is going to college for media or game design. I would focus more on original content that is more polished.
Joyride - Its a really fun and interesting idea, but the video is half fluff and the rest is maybe screen shots? Also, the graphics are less polished than the rest, making it kind of rough for a portfolio. You might not have anything to do with the graphics, but that just means you need to get on the case of whomever is so you can have something prettier to show. If you're the designer, that means you have to bring the hammer down and get the art work all on the same page and up to a standard. One thing I would probably do with this game is take it out of the portfolio for now until it gets some more polish and from your resume it seems that it is still an on-going project.
Pyroclast - Another interesting game idea with "meh" graphics. One thing I think would have been great to see here was a video like everything else. The reason I bring up graphics again is because even if you aren't in charge of them, those graphics are what represent your game and ultimately tell the quality of the work done on it to potential employers. You might have done a phenomenal job on your part of the game, but if everyone sees bad art, they'll think the entire game is unpolished.
Massteroid - This one is pretty well polished and has some awards attached to it which easily makes it the piece you want to showcase. I think you even did a good job on the video by having straight up game play, and also with the write up by really explaining what you did, some challenges you faced, and how you over-came them. Maybe adding some links to external sites that have your game listed as winners of those awards will help?
Anyway, my over-all impressions of your portfolio is that you're not really showing what you want to show. From your headline, you say that you're a level and content designer. What you're showing is a couple of space shooters with mediocre to decent looks, an incomplete (but cool idea) racing game with inconsistencies in design, and some pretty beginner level stuff in Maya and Skyrim.
Also, show more stuff! Your portfolio is pretty short on content, so try to fill 'er up!
If you want to help show you're a level designer, I would create some top-down maps of dungeons or levels for a game, then have a fly-through of the level. Also, show some completed game design documents to show that you have the design skills to complete one that makes sense. And finally, I know I've said it a couple of times, but I strongly suggest you get some polish on those games. As a content designer, you need to hold not only yourself but your entire team to a standard. If they can't create content that meets your requirements, then encourage them to practice, do multiple iterations of the content, and if you still can't squeeze what you want from them, then maybe pass the art reins over to someone else. There may be butt-pains flying around, but not everyone is an artist just the same as not everyone is a programmer. Just don't pander to others delusions or whining. Ultimately it is your career and the game that you need to look out for, and if someone can't cut it, than it isn't good for you or the game.
I hope I was some help and that I didn't get you mad. I think you've got some good stuff on there, just not quite enough or quite right to show that you are a level and content designer. It feels fairly unfocused on what position you're looking to fulfill.
tl;dr - your skills are being represented by sub-par art and you aren't showing what you want to show for level and content design. add more content will help.