With that intensity, management has developed unrealistic expectations of their employees. They do not mind taking advantage of you. This could be financially, your personal time, or just exploiting you and your talents until you have nothing left.This goes beyond the workhorse mentality, and borderlines inappropriate behavior.
Office politics are very present. Old rivalries and mean "girls" are everywhere, they will use you like a pawn. A strong HR department is very needed, but they can't or wont commit to that. This is a company that is struggling to move forward and adapt appropriate business management techniques for their size. We can only hope they can get that together. If they did, they could truly be a great company to work for.
Continuing with the lack of HR initiatives there will never be an opportunity to advance. Do not think that you will move up in the company. There are no promotions or salary increases. If someone leaves, you will absorb their responsibilities with no hopes of a pay increase. In fact you may even be demoted when it comes time for your salary negotiations which you must beg for. Prepare to stay in the position you are hired and the salary you are first able to negotiate because it will not change.
So somewhat harshly but with strong word of warning forget the living wage, personal time, or any self worth you thought you had. Unless you are part of the executive team, because then you are awesome.