I'm trying to position myself to apply for a US MBA next year but I have a question about how to frame my work experience and if there is anything I can do to help me stand out.

My main concern is that the schools will most likely not know any of my recent employers. Although I am American I did a master's degree in marketing at a not well known school in Germany which allowed me to get a job at a small international startup in Berlin. You wouldn't know the name. I was there for almost three years. I was a jane of all trades focusing mainly on marketing but they eventually started calling me a program manager. I left that trainwreck to pursue funding for my own venture which sadly is fizzling out after almost two years.

I took the GMAT earlier this year and scored 660. I could probably do better with some preparation and focus.

As I approach this next step I am looking at returning to the US next year for the fall 2021 MBA intake. Wisonsin, Babson, Darden, with Cornell being my ideal school. However, I have strong misgivings about applying with work experience at companies that are so unknown. Before I did my master's degree I worked for a better known video game company, which I guess is notable but I don't have a lot to show for that.

Any advice on how I can pitch my experience? Will they ignore my application for those with experience at bigger firms?

I'm not sure what "a not well known school in Germany" means. Any state university will be fine. A private Hochschule over a chicken shop won't be so great.

You can't do anything about the firms. Think about the schools. Look at what they want. Sing your song in the key of their desired attributes. Use the salary average and salary growth to calculate the pre-MBA salary. Schools with low starting salary will be more open to. Also, schools with fewer international students will be more open to you.

It's less about the 'names' of the firms as it is about the quality of the work experience, and how good your letters of recommendation will be.

In terms of how to discuss your work experience in your essays, etc., try to frame it in terms of growth: discuss in concrete detail your promotions and leadership skills, and how each experience built on the previous one. There's a lot to be said about somebody who started (I would imagine) small at a video game company, grew into a program manager, and then launched their own firm. That's a compelling story.