EDIT 2/19/18:
This is the final demo build I'll upload for this contest. Game's not finished, but it's somewhat balanced and there's a miniboss to beat.
Here's what I've got done so far for the One Map Contest. It's playable 'til the first miniboss, and you can wander around in the other unfinished areas too after you beat said miniboss.
There are some known bugs with the bat's accuracy-reducing special attack, I'll have to figure them out later though.