Your first step is to figure out what elements exclude people. Personally, I think your current activities have strong elements of competition & machismo. There's also a large skill-based component to some of them (it's hard for someone new to computer games to have fun while joining a bunch of experienced gamers playing Halo). So your new activities should favour things that prioritise other elements: non-competitive, accessible to beginners, and not so bro-like. Here's some concrete suggestions:

- Handicrafts. Get some supplies that let people make something. Sculpey, for instance, sell kits that come with clay & instructions (http://www.sculpey.com/product_category/kids-kits/). Creative types can freestyle it; beginners can follow the instructions. Plus everyone gets something they can take home or keep on their desk afterwards as a memento. It doesn't have to be clay - there's many other options like pipe cleaners & fuzzballs, felt cut-outs, picture beads, and origami.

- Learn a skill. If you've got a budget you can hire an outside expert, but you can probably find someone inside the company with a good party trick. Get a magician to teach some basic sleight-of-hand, a juggler to teach juggling, or an entertainer to teach some balloon animals. There's also cookery, improv, flower arranging, astronomy, and many more.

- Play with toys. Find some unusual/expensive items that your attendees can play with throughout the night. An Oculus Rift, a 3D printer, a unicycle, an Apple watch, Google Glass, a photo booth, a double-necked guitar, a Segway, a candyfloss machine, etc.

- Engineering games. Given 1 roll of stickytape and unlimited straws, what's the tallest tower you can build? Given half a pack of blu-tack and unlimited paperclips, what's the widest gap you can span? Given 10 sheets of cardboard & a craft knife, how many coke cans can your structure support?

- Movie night. If you've got a projector, a stereo, and some comfy chairs in your office you're in for a treat.