Good
Very well thought out concept i agree with Vortexphoton however some upgrades would be very nice as well as dont havedifferent enemies shooting the same red bullets change it up a little bit. As for challenging? I am a long term player of Geometry Wars Evolved 2 for the Xbox 360 so in comparision there was no challenge on this my suggestion is possibly make a number two with upgrades a little better graphics and some bosses perhaps. That or pick up an Xbox controller and play the worlds greatest arcade game :D all in all a good game.