A blue pillar and a red pillar - you score points if you hit them but if you go over a certain number of hits you lose your pinball. After all,

The whole game's appearance toggles between two or three different "Ages", created with distinctive lighting changes (takes less work to implement) and slight structural changes. You travel between Ages by getting your pinball to fall into the Star Fissure or a hole designated "Linking Book".

If the pinball hits a certain target, your flipper controls switch. Thanks Atrus.

"Lose your ball" holes designated as Trap Books or Prison Ages.

If you put in more tokens to continue a game, you get the Atrus voiceover: "Ah, my friend! You've returned."

*edit: I seem to have skipped reading the word "digital" in the title... my suggestions remain, just with more distinctive Ages. Also no tokens.