Features request (can be applied to any control panel what people trying to develop on any language):
account registration with access only to login table (user, pass, captcha, email confirmation, sex, birthdate (optional)), referral nickname).
account management: reset pass, re-sent login to email
character management: reset hair style, hair color, cloth style, last map, save a map, homunculus/mercenary/pet (clean it)
master account inside which you can make a game accounts
do not use any bloated shit, and use only the latest modern and well-tested components.
do not make bloated code or features.
html5/less/css3/ (optional) + js
follow any modern/good/ easy to use or modify templates. This is a key feature. If devs can build beautiful websites easy - your CP will grow.
If not - y our CP will die.
security, verify ALL user input, do not trust to users at all. Use as less code as you can, verify everything
caching which will work with speed, Nginx FastCGI, or redis, or anything else (important against DDOS attacks)
donation module: paypal, stripe, cryptocurrency, any other payment method.