woah, really cool. something in the main menu really made my computer act up at the beginning was fine after i reloaded it. i couldn't figure out how to use items like the broom or the fire extinguisher after grabbing them, i just used the level select to get passed the storage room.
There should be a tutorial in the main menu. In the first level there are a lot of latter on the floor - it's all buttons that you need. press "q" to open inventory and then press "E" in the right place (use broom on a shalf). And you can open any level in the main menu so please - try other 2 levels. They should work just fine)