Turbo mode not unlocking?

[rat_v1.5]

I've beaten Arcade Mode on Hard twice now, but Turbo Mode hasn't unlocked and I haven't gotten the Speed Demon achievement...

[cknight]

Oh no!

Did you complete the game from the start, or from a checkpoint?

Cheers
Charlie

[rat_v1.5]

I never start from checkpoints (i'm also going for Hardcore achiev)

[cknight]

Hmm, maybe you need to beat it on insane difficulty? i actually can't remember! I'll find out...

Cheers
Charlie