A core of strong personalities dominate the company culture. Management up and down the hierarchy tend not to favour 'quiet' types very well. Favoritism is endemic. Strong work ethic and actual talent are not enough to succeed here - you will also be expected to brown-nose and boot-lick a little to remind the higher-ups of how valuable you are.
Management also possess the awful habit of insisting the company plans carefully, before going back on promises and sometimes even whole project roadmaps. Knee-jerk decisions that benefit nobody are commonplace. Communication from the top can also be lazy and poor, and you will be blamed (and made an example of) for your failure to follow the incoherent directions that trickle down. This is especially true if you haven't managed to follow the crucial guideline stated at the end of the previous paragraph. At times, it feels as though the company is performing well despite some of the people up top, rather than because of them.
Finally, despite the company promoting a 'good work/life' balance as one of their key selling points, development death marches can and will happen, thanks to the regular mis-steps management make. All too often, the company is Agile in mantra alone.