MArcomage

There is already a Card called "Haste".

Thanks. This time I have ensured that there is no other card named 'Overtime'.

Perhaps you are expecting that I put anything more in text.
In fact, I won't for the moment (obviously, I'm open to suggestions). The idea is that this card can complete the cost of another card to be played in the same turn.
If you think that it's too strong, I may add "Tower -2", "Enemy stock +2" or something like that. Or I can simply move the card to "Rare" section.

I assumed it simply gave you a free turn of production. What you're describing now suggests copying another card's effect, long established as not implementable.

"The idea is that this card can complete the cost of another card to be played in the same turn."
I didn't mean automatically. Yes, it should give a mere additional turn of production. But this can be useful to pay the cost of another card, can't it? :)