Beat Hazard 2 Dev Blog: Which feature next?

Here's my latest developer blog. Early access went well and I've got rid of most of the bugs.
A big thanks to all of you that have bought it. I hope you're having fun!
I've just added 4 new enemy ships. Now I'm looking at what to do next.
Help me decide which feature to I do next?

1) Workshop & custom ships
2) Articulated bosses
3) Local co-op play
4) New perk weapons

More details in the video.
Leave a comment or use the twitter poll: https://twitter.com/ColdBeamGames/status/1062701353296936962