This guide may be helpful for someone playing on Easy, but on Legendary you have to have a strategy. A strategy, is not included in this guide. An excerpt from the guide: "Two more troop carriers show upalmost simultaneously, in spots thathave already hosted alien infestations.You know what to do." For those who know the game, troop carriers are equipped with 2-3 Elites, 2-4 Jackals, and 6-7 Grunts, one troop carrier is difficult to get past, but two is almost impossible. 'You know what to do' is their suggestion on how to get past this difficult part(on Legendary). I would not recommend this guide at all. The only thing helpful is at the very beginning, where it lists some effective weapons, and it has maps of the levels, other then that, there is no guide.