Copied from the agreed story (STORY.md) and the rule sheets
(2026-10-07); those two win if this drifts.
The slings are background most of the game; their story job is period 2 and period 3.
- Period 2: 2A, the Fifties, is Repulsion Gel on the pops and slings (the gel music builds
with the hits).
- Period 3: the slings are the crushers (short turret yelps, "please be careful").
- Period 1: Portal 1's mild safety reminder now and then.
- Co-op: Mobility Gels (course 5).
- sequence
sling_combo — "Sling Combo" mechanic named explicitly in board Overviews.xlsx -
back-to-back sling hits within a time window. MPF's sequence logic block (time-pressure, N hits
within a timeout) is the right fit, not a plain counter - confirmed as the standard real-machine
pattern for this kind of combo by the pinball design research
(design/research/portal-themes-and-pinball-design.md Part 2).
DRAFT, needs a real game-balance pass with the user: 100/hit per sling (unchanged from the old
base.yaml placeholder), +750 combo-complete bonus for 3 hits (either side). Implemented in
modes/slings/config/slings.yaml as a sequences: logic block - NOTE: the "back-to-back within a
time window" part of the mechanic is not yet implemented, see that file's comments
(logic_block_timeout doesn't mean what its name suggests here - it starts from mode/logic-block
enable, not from the first hit). Flagged in TODO.md.
From rule-sheets.md, not built yet: the rules above are what the mode does
today. Counts, timers and scores are drafts for the balance pass.
- 2A gel test: 30 pop and sling hits (the music adds a part at 10, 20 and 25).
- Co-op course 5: 30 pop and sling hits plus 4 orbits.
- Slide: modes/slings/slides/sling_hit.tscn - implemented with a blue bounce-arc icon (plus a
fainter echo arc implying the combo building) on a blue-tinted dark panel, per the approved
"Aperture Display Signage" graphics proposal. Plays on the combo-complete event.
- Show: modes/slings/shows/sling_hit.yaml - implemented (2026-08-27) as a blue-white-blue quick
double-pulse per hit, per the Repulsion Gel motif.
- Sound: machinefolder/sounds/sfx/slings_hit.wav (per-hit) + skillshot_test_chamber_pos.wav
(combo-complete) - implemented (2026-08-27) from the user's Portal 2 sound extract. No clean
"springy boing" exists in the pack (Portal isn't that kind of game) - a synth blip stands in.
DRAFT pick, user plans to review/adjust manually. Picked to replace it (owner, 2026-10-24, sound library): sfx_chicken_tube
(0.6 s, the tube's pop; design/callouts.md's effects table).
Onshape CAD confirms Slingshot Rubber Left/Slingshot Rubber Right as real named parts (~2.05" x
4.45" each) in the lower-middle of the playfield near the flipper zone - directly confirms the shots
above with no ambiguity. See design/research/onshape-cad-findings.md.
- 2026-10-07, story pass: Repulsion Gel (the first proposal) is confirmed, for period 2 only.