When CMSF was first released (2007?) I played the first couple of missions, then put the game back on the shelf, where it remained until the marines module was released. The game seemed very different to CM1, almost 'bare bones' in lacking features which were standard in the older games, also it was 'buggy'. I decided to give it another try when 'marines' was released and I loved it, there had obviously been a lot of post release development going on between the two releases, and it has only got better over the years since (there are still a few things that CM1 did better in my opinion). But onwards and upwards to CM3!