Achievement Unlocked Part 1

Add this game-feel effect to my 2D game: Achievement Unlocked — Slide-In Toast.

Reference scene (context only — map it onto my own characters and sizes):
A side-scrolling 2D run. Art is pixel art: the hero is 12×13 art pixels drawn at 7px (84×91px on screen). All sizes below are screen pixels inside a 438×190px view — scale them to your own screen. Times are seconds, t = 0 is the moment an achievement unlocks. The hero runs to the right in place (2-frame run cycle, switching every 0.125s) 90px from the left edge while the ground scrolls left at 192px/s and the far hills at 60px/s. Stars (10×10 art pixels at 4px = 40px, soft gold glow radius 30px at 16%) float 192px apart and bob 4px twice a second; one is picked up every second, 52px in front of the hero and 54px above the ground (a tiny burst of 4 cream sparks), and that unlocks an achievement. The notice sits in the top right: a 290×72px toast 14px from the right edge and 8px from the top, so it never covers the hero's face. Toast: dark #2a1d16 rounded box (radius 12px), 3px gold #FFC24B border, soft shadow (black 35%, offset 4px/6px), a 60px-wide #3a2a1f icon panel with a pixel trophy (12×11 art pixels at 5px), 'UNLOCKED' in a 3×5 pixel font with 4px cells in gold, and the achievement name in 5px cells in cream #fff6d8. The 12 names cycle (FIRST STAR, COLLECTOR, NO DAMAGE…). Unless noted, the notice leaves between 0.7s and 0.85s.

The effect:
Slide the toast in from the right: x offset 300px → 0 over 0.15s with easeOutBack (c = 1.70158, about 10% overshoot past its spot, then back). …

The rest of this prompt — exact sizes, easing, colors and particle counts — and full prompts 2–6 are in the pack.