One thing I would like to see incorporated is the different equipment manufacturers from the video games(Jakobs, Anshin, Vladof, etc.) They could add a lot of depth to a pinball adaptation of this franchise. Before the player plunges ball 1 they get to cycle through with the flippers and choose which "brand" of weapon (ball) they want to start with.

The game will play slightly differently based on which manufacturer the player has chosen, giving the player advantages during certain game modes and disadvantages during others. The individual players strategy will determine which order they want to tackle game modes and therefore their choice of "weapon." The Loot Chest toy (which I agree is a must have for this theme) could give the player the ability to switch manufacturers mid-ball. I would make it so that the chest would become available after the player makes a short series of qualifying shots, then they could hit or enter the Loot Chest to collect any earned bonuses, mystery awards, etc. and may choose to change or keep their current "weapon" before resuming play.

Some examples of how this might work:

Jakobs weapons are known for doing high physical damage in the game. While this manufacturer is active, flipper power might be slightly stronger, making some shots easier or even previously impossible shot(s) possible. Any bash toys/repetitive qualifying shots could take fewer hits to advance.

Maliwan weapons have effective elemental abilities that do supplemental damage over time (DoT). This manufacturer's perk could be set up to be best used during some sort of boss battle mode, or award bonus Bandit kills earned for making ramp/loop shots (similar to Walker kills in TWD) that increase the end of ball bonus and/or multiplier.

Anshin equipment in the game provides health recovery. This manufacturer could make it easier to earn an extra ball, multi-ball or re-activate an outlane kickback if one were included. The trade off to this could be that "damage" done by the player might be reduced, requiring more hits to qualify high-payoff shots or down bosses.

Just my idea for a way to make this game tie in well with the franchise. I think it would not only provide a strong connection to the theme, but also make for a fun and unique game mechanic that people familiar with the BL games will appreciate, and add a layer of depth to individual player strategy that all pinheads will appreciate. Use it or don't, either way, best of luck with the project. If a BL game were to make it all the way to market I'd buy it in a heartbeat.