Crysis

This is a story related achievement and cannot be missed.

SPOILER

Mission: Reckoning
After completing several of objectives on the ship you will be prompted to go to deck for the second time to kill the intruders. Before you do so grab the TAC (the weapon you´ve seen previously when they upgraded your nanosuit). On deck grab a minigun and a gauss cannon and shoot the huge alien known from the previous chapter) until it goes down. For the second boss battle restock on ammo and hide behind some wrecks. Shoot at all of its cannons and if special parts of its surface are highlighted aim with the TAC (actually you have to aim like 3 seconds and then you can shoot). Do this to the two arms, the head and its body. Run over to your VTOL and watch the last cutscene but the achivement will pop before.

In this mission there appears to be some annoying bug which makes you unable to finish the game.If you are missing the TAC gun and don't know where to get it, read this.

There is major bug in the final mission, when the island is nuked and you are instructed to go to the deck, before reaching the deck a bug appears if you stay in more than a few seconds in the lowest chamber of the deck when you run down the stairs, the scripts kicks in which appears admiral being attacked by the alien and he dies, if that happens after nuke and before getting TAC gun you need to reload last checkpoint or even restarting the whole level again.

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Dr.Jones