In the last 2 years my company has developed a boxed and full-price computer game. All the software development has been done collaboratively by me and my co-developer. We know each other from university and got hired at the same day to equal conditions and we share the same responsibilites including the decisions of what technology to license and how to spend development resources and even how team-workflow is organized. But I struggle to find the correct wording for my position. Can I call myself a senior developer with only 3 years working-experience? Can I call myself lead programmer if I don't really have a team to "lead"?

All these fancy names used in the industry (Technical Lead, Development Lead, Software Architect) seem to imply that you aren't actually coding anymore or have staff under you. On the other hand titles like "Programmer" or "Software Engineer" seem to imply that there's someone between you and the project management. That makes it hard to fill out a resume or even the badges you typically wear on conferences... people tend to judge you by your title and I'd like to avoid confusion where possible.