I'm guessing the accusation is criminal in nature? i.e. not a claim made as part of divorce proceedings or as part of a civil case.
The key question here is how you got out.
If you were simply released on a promise to appear without any conditions (not brought before a judge) then theoretically speaking you can leave as long as you come back when you're supposed to.
However, if any conditions were attached to your release, specifically a condition that you don't leave the territorial jurisdiction where the alleged offense took place, then you may not leave the city, let alone the country. If you do you will be violating the conditions of your release and are liable to arrest and detention if discovered.
If you were brought before a judge and either released on your own recognizance or made bail, there would almost most certainly be a condition that you don't leave town.
Simply put, to determine whether or not you can legally leave the country you need to check the conditions of your release.
Even if you can legally leave, you still need to appear in court on the day you're supposed to. If you fail to do so then the most likely outcome will be a Canada-wide warrant for your arrest, which will most likely be carried out on entry to Canada.
Failing to appear, and more importantly fleeing to avoid prosecution are serious charges that can be brought independent of the assault charge. Not to mention if you attempt to flee and are arrested, you could be deemed a flight risk which would most certainly mean a much higher bail amount.
If it is a bogus charge, then appear and defend yourself and get yourself acquitted.
If it is not a bogues charge, still appear and do the time. It will most certainly be less than whatever you will get if you flee/try to flee the country.
If you are not a Permanent resident or a Citizen of Canada then fleeing will jeopardize any chance you have of coming back to live in Canada as a free man.
One important note I want to make is that while others have very rightly said that you will get into trouble if you don't appear for your court date, if a condition of your release was you staying within certain territorial limits, then you cannot leave regardless of whether or not you intend to show up for your court date.