Epos Now Software Developer interview questions

I was reached by a very nice external recruiter at first. He sent me some questions related to software architecture, algorithms, data structures and Linux. They were mostly sort questions. I sent him back the answers and he arranged an interview between me, the head of development and a software engineer. This interview took almost two hours and they asked me to develop some parts of the game minesweeper using some OOP techniques. I could choose my preferred programming language for doing it. Then they asked some questions about Linux commands. To be honest, I weren't aware of doing something wrong, to say somehow. I didn't do the exercises perfectly, but good enough taking into account the pressure inherent to the situation and the short period of time for doing it. They didn't treat me in a bad manner, but I wouldn't say that they were friendly neither. I left the interview with the feeling that I may not fit the atmosphere of the team. I was told the next day that they decided not to continue with my application, so I received pretty quick feedback.