I believe it. I had programmed in C and C++, Visual C++, Visual Basic, but it took me 3-4 weeks of reading about the 6502 and the 7800 in particular to make a single dot appear on the screen. I'm not a professional programmer though.
Very nice work btw. PacManPlus should start his own company. I'll invest $1000 - more when I get my first paycheck for my first "real" job.