It's a perfect candidate for speed runs now. Get yourself a new pair of batteries and try get the furthest you can!
What model number or type of battery is it? I don't want to open it to check, risk damaging it and being unable to play it completely. My Silver's cell is loose/empty too, I simply bought Crystal. Blue is still going strong.
If you want to check if your battery is loose, shake your cartridge. It if rattles then your battery might be loose. You'll also notice your game is gone... This is what happened to mine, the save stayed until it was rattled, had a save for a very long time and it disappeared. The same happened again.