Kylotan of course makes a lot of sense; interviews are often short, and that time should be used to demonstrate the breadth of your experience. 8 levels is almost certainly 7 too many.

If you can show all of the key areas mentioned above, input, ai, sound, graphics, user interface, etc, then you're demonstrating your potential versatility as a junior programmer, and that you at least have a cursory understanding not only of how each area works on its own, but also how they all interact and work together to create a complete game. Kylotan is right, your first chunks of work in the industry will likely be with a pre-existing codebase, so the more you know about all of the different parts of a game you're likely to come across, the quicker you'll be able to get your hands dirty and make a tangible contribution.

Which is of course great for you, and exactly what an employer will want to see.

Something I noticed. You have a flash portfolio. From what I've heard, you should make a portfolio that's accessible by any browser without the need for plugins.

On the video, your background music is kind of abrasive to my ears. I'd maybe use something that's a little more docile or none at all. It's not like you're applying for a marketing position. You might consider going into more detail about the engine instead of the musical parts.