Leaving without getting the core is the same ending, just no revaltions. Getting out of the bottom floor is hard, if you have every upgrade its just timing the elevator right and I still don't understand it.
Good game has great potential, a power-up to increase a rounds time would be nice, or a freeze time. 4/5. Definitely needs a story or multiple levels. Nice to know that this is only the first game by Failsafe.