Generally good ideas: No random death trolls. Check for bugs. Minimize waiting, confusion, and repetitiveness when they're not interesting. Have a theme. Have elegance. Don't force the removal of power-ups. Make it hard to die right at the goal. Have a flagpole 1-up challenge. Don't show the goal until they can quickly reach it. No forced manual restarts / exits. Use Diddy! 8} sry