The only reason ED's save file was so big was the ability to save anywhere. If that wasn't there, it could have easily been scraped down to 2-3 blocks. I haven't played MGS, and I know almost nothing abpout it. From what I can gather, it has a linear storyline with lots of set events. If it has a non-existant or linear (like Metriod Pime's) inventory system, and set save points, it will be tiny. If someone could tell me the nature of the inventory system, the save system, the naming system, the linearity of events, and a rough number of each (e.g. there are 20 items, and 100 save points or whatever), I should be able to work out a rough number of blocks for you.