Before you jump into the online world of Aliens: Colonial Marines, you'll want to play through the single player campaign. Marines can earn experience in both single and multiplayer, meaning you'll be able to have a consistent loadout whether you play online or off.
"The great thing about that is, if you are more into single player, you can get just as many upgrades and weapons before you even play multiplayer for the first time," senior producer Matt Powers told Shacknews.
Naturally, Marines and Xenomorphs have different upgrade paths, and the experience earned as a Marine won't count towards developing your Alien. Xenos are playable only in multiplayer, so "it also forces you to play multiplayer in order to upgrade your Xenos, so you have this variety of gameplay in the form of two distinct upgrade paths."
For more, read our impressions of playing as a Xenomorph in our latest multiplayer preview.