EXACTLY the same problem i had with the Lego Star Wars 3 demo.. i was on both missions and quitm because i played for literally 2 minutes and got to a point where i was like "?" They would just not tell you where to go. And i dont know why they do this. Kind of stupid though.
Ehh i am waiting for Modern Warfare 3 i played the series at game number 3 and loved it ever since.. i got really interested in Call of duty 4 Modern Warfare and then played through the present games... and NO i dont want to wait another year!