I was able to glitch the game.
At the second dungeon my ball got stuck between the two bottom left skeletons. It bounced between them all the time and wouldn't stop. I got an incredibly high combo as well as an ridiculous amount of points and about 20 dungeon balls. After I left the dungeon I got about 40 balls, giving me the possibility to keep playing forever.
Aside from that, nice game, but in my opinion it's too easy. Aside from the dungeons (where it doesn't matter because I can play them over and over again without losing any non dungeon balls) I hardly lose any ball and I really am not a great pinball player. But you got a lot of great ideas, put some more work into them and this game will become really awesome.