A physics sandbox starring the Jamblobs, twelve musical characters. Pick something from the shelf at the bottom, then click (or tap) in the sandbox to drop it. Drag things around with Grab.
The shelf: swipe it sideways to see more Jamblobs, or use the ‹ and › arrows at either end — hold one down to keep running along. Tap a Jamblob to pick it, or drag it straight up off the shelf and into the sandbox to drop it there.
Jamblobs get hurt by falls, heavy objects, spikes, saws, fire, lava and explosions. Their health bar shows when they are hurt. Heal brings them back.
Night Mode: press the moon button (or H). The stage goes dark and the Jam slows down.
Arena: cycles the stage size from Small to XL. Everything stays on the floor; zoom out to see it all, zoom in to play.
Jam: every living Jamblob performs its loop, beats, effects, melodies and vocals together, at 120 BPM (96 in Night Mode).
Keys: Space pause · Esc back to Grab · R rotate the item you are placing · Del delete the hovered thing · H night mode · J jam · 1–7 tools · A bigger arena (Shift+A smaller), +/− zoom, 0 reset, mouse wheel, arrow keys or right-drag to pan; pinch and two-finger drag on touch