Just a suggestion, but considering that you used some content from one of your previous games Schwing, why not grab some inspiration from SwordFace. Maybe after collecting (touching) all melee weapons, you get a swordface hat/mask. I haven't played too much of too much of SwordFace, but I'd love to see content from there too if at all possible.
Loving 0.0.6! Can't wait to discover more, I'm glad you didn't post the changelog right away.