I tried really hard to add melee. I had it working well with a double-tap of any d-pad direction, but the engine's limit of 5 unique projectiles per scene locked me out of doing that sadly. I may come back to it again and give it another go, but I'd really like to work on the next level and get some new content out there!
BTW, there is a cool update to the first two levels coming in a few days.