Incredibly cool concept with a lot of potential, the emphasis on speed in a card game like this feels quite fresh.
Even if the art is placeholder it still looks very good.
I think some of the buff cards could definitely be much more powerful to encourage thinking a bit more, for example "plan" giving +1 to next 3 cards for a cost of 3 feels very weak since that's only 1 point per time unit which is more expensive than all the basic cards.
I would say the cards need art to be distinguishable in the moment but I assume that was the art not being able to be done due to time constraints. (Also the cards should probably be spaced out a bit more or vertically ordered the other way around so it's easier to see the timers)
Overall very interesting concept with good execution, just needs a bit more balancing.