Hi there, I'm a little confused about the campaign structure of TA. All missions are available from the start, when you beat a mission you see that all the ones you've already done have a thumbs up, those where you failed get a thumbs down. It's a bit untypical, so I'm wondering if the system has some deeper meaning that is not apparent at first (i.e. outro only playing when beating all missions in a row or something). Were all missions also instantly available in the original release?

They were. Kinda nice since you still get access to the rest of the scenarios if there is one that you simply can't beat.

Hm, not the kind of solution I like. ^^
But thanks for the answer!

They were locked originally, but it was patched so you could attempt them in any order.

It was when one of the expansions came out, I bought the full pack when it came out and everything was unlocked when I installed them

I stand corrected. I mistook "original release" for gOg's release. Thanks for clarifying.

Both are right, actually. Originally, the game had locked missions that only became available when you beat the one before it, but there was a password you could put in to unlock them all. When Core Contingency (I think, I never saw it alone) they made it so that all missions were unlocked.