Custom cards should have their own graphics, or perhaps a different colour, the tool icon isn't obvious enough. It is frustrating when two cards with the same name and picture have different functions. It means I must check every card individually and read it's description to know what it does.
It would be cool if you could support scaling the graphics in line with the level of scaling in chrome/firefox. The deck editor is a nightmare in 1920x1200 resolution.
Often, the display is too cluttered to see enemy bullets. You don't need the numbers showing how much gold has been collected, just have a table from the frontend showing how much each gem is worth. DXU upgrades should be a different colour to enemy bullets.
The guns are highly satisfying and I really enjoy the combat. It's let down by the platforming elements - the character is very hard to control and these sections are very frustrating. Less platforming, more shooting
 "Dungeons of Kong"){kind=icon}
 "Totemica: Duelist"){kind=icon}
 "HD Xyth"){kind=icon}
 "Vulpin Adventure"){kind=icon}
 "New Star Soccer"){kind=icon}
 "Heavens"){kind=icon}
 "Mecha Arena"){kind=icon}
 "Dragon Rescue"){kind=icon}
 "Frantic Frigates"){kind=icon}
 "Plazma Burst: Forward to the past"){kind=icon}
 "Flagstaff: Chapter Two"){kind=icon}
 "Arkandian Crusade"){kind=icon}