I've played all levels extensively, and from what I've played and seen in game, it's looking very bright, and I can't wait for new content. I thank you for making this little gem.
Now I noticed something in the first level, that you can do to actually go out of the map bounds. On the lockers you can actually walk on top of them (because they're at an angle, and I guess characters can walk on slants). You can actually walk outside of the map, and you can't get back in. Running away from the level only gets you inevitably stuck.
I haven't really noticed any other oddities other than that. The other levels are quite solid and I like how you've made the game have a lot of freedom (hence it's name I bet) on the customizable options. You've even gone off and included weapons from custom scenarios (such as the Snyper pistol from EMR).
I love what you've done, and I'm going to keep loving what you do with this. I can't wait to see the final product.