Slopes would be nice to have, for sure. But it's a huge job to make everything work 100% properly, and right now other stuff is more important, that's why I don't plan to implement slopes any time soon.

LAN-based multiplayer (like the original DOOM had) is planned for the version 1.32 release. The code is partly done and just needs to be finished.

Internet multiplayer works in a completely different way, called "client/server", and it requires massive changes to the code. Also the whole culture surrounding online games is really not my scene. Hence internet play won't be added. There are other DOOM ports good for this.