Yes, 6 months is possible. The MSX contests are usually 9 to 12 months.
I made Quasarius in 3-4 weeks and Roadtrip in like 10 days. I know none of them are great games, but it shows its possible to do something good in 6 to 12 months, but it may be hard to keep working for something during this time without any kind of incentive. I still haven't played your Bomb Jack game, but from videos its obviously its awesome
