Dragon Sweeper — 365 Perfect Run

Goal

Clear the entire board and kill the dragon last for the maximum score of 365. It's a deduction puzzle, not a luck game — the layout follows fixed rules, so a clean run is always possible.

Core principles

Information > Gold: Always prefer revealing new tiles and hints over killing monsters you already know.
Use the number tiles: Each number = the sum of monster strengths (P) in the 8 neighbours. Combine it with the placement rules to deduce which tiles are safe.
Spend HP before levelling: A level-up fully heals and gives +1 max HP, so drain your HP to ~0 first — don't waste HP you could have used.

Early game (levels 1–5)

Click the two orbs to open up safe areas.
Find the Rat King and Purple Mage fast — their scrolls reveal all rats / all slimes, which is a huge chunk of free information.
Lean on the placement rules: rats face the Rat King, gargoyles spawn in mirrored pairs, slimes sit on the edges around the mage, and Romeo & Juliet mirror across the Y-axis.

Mid game (levels 6–10)

Mark high-P monsters instead of fighting them early.
Bank HP against walls so you hit ~0 right before a level-up — that squeezes the most value out of each level.
Hunt the Gnome into a corner of empty tiles for the 10 gold.

End game (levels 11–15)

Kill the Lich at exactly 11 HP, then use its scroll to defuse every mine — each defused mine is 2 free gold.
Use any leftover heart scrolls only at 0 HP and at the highest level possible.
Clear the remaining monsters from low P to high P.
Kill the Dragon last.

Luck factor

Only wall-gold drops vary, and that affects scores above 365 — not the clear itself. Apart from the odd ~85 %-safe guess in the opening, the win is pure deduction.

See also the monster compendium. A guide for Dragonsweeper by Daniel Benmergui.