I keep getting this error while compiling. Any ideas?

Sprite.h:4: error: variable 'flappybird_frame_2' must be const in order to be put into read-only section by means of '__attribute__((progmem))'

 static unsigned char PROGMEM flappybird_frame_2[] = { 0x03, 0xF0, 0x0C, 0x48, 0x10, 0x84, 0x20, 0x8A, 0x40, 0x8A, 0x40, 0x42, 0x7C, 0x3E, 0x82, 0x41, 0x84, 0xBE, 0x88, 0x41, 0x78, 0x3E, 0x07, 0xC0 };
                                                 ^
Sprite.h:5: error: variable 'bar_bottom' must be const in order to be put into read-only section by means of '__attribute__((progmem))'
 static unsigned char PROGMEM bar_bottom[] = { 0xFF, 0xFF, 0xFF, 0x42, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E, 0x7E };

replace all "static unsigned" on "static const unsigned" in the sprite.h

great project! will it work with other types of screen? (adafruit's 3.2" tft touchscreen, for example?)

I built it and it works great. However, it really needs a CD4050 level shifter between the Arduino and the Nokia LCD to drop the signals down to 3.3V. My display started getting dimmer after 20 or 30 minutes of running. I added a CD4050 and the display returned to normal and now runs without dimming. Here's the link to a page that covers the wiring for the CD4050 and a Nokia 5110 LCD:

https://learn.adafruit.com/nokia-5110-3310-monochrome-lcd/wiring

Be mindful of the connections to your display, mine didn't match the example. Other than that, the code compiled perfectly and the game plays very well. Great job on a cool project.

I've got all the three parts at hand, but I haven't made it yet. I like your style of coding! Nice and tidy, to the point where comments are not needed. If anyone ever ask me how to get into uC or Arduinos, this project will be on my list of tips. Thanks for sharing!

If you're going to drive yourself crazy playing a game, it should at least be on your own hardware. Great job ensuring an Uno will be used until it dies! This would make a great gift with a little packaging.

Oh yeah... I ordered the LCD! Let the tinkering begin.