Dr. Mario Cheat Codes & Secrets
Complete collection of cheat codes, passwords, unlockables, and hidden secrets for Dr. Mario (1990).
Level Select
Dr. Mario builds level selection directly into its configuration screen — no code required. From the title screen, press Start to reach the game setup menu. Use the D-pad to set your starting level anywhere from 0 to 20.
| Starting Level | Virus Count | Difficulty Feel |
|---|---|---|
| 0 | 4 viruses | Introductory |
| 5 | 24 viruses | Beginner |
| 10 | 44 viruses | Intermediate |
| 15 | 64 viruses | Advanced |
| 20 | 84 viruses | Maximum standard |
Higher levels do not simply add more viruses — they also distribute them deeper into the bottle and in more awkward arrangements, making clean line setups progressively harder.
Speed Settings
Speed is selected on the same configuration screen as the level. Three options are available using Left/Right on the D-pad:
| Setting | Capsule Drop Speed | Best For |
|---|---|---|
| Low | Slow | Learning placement, beginners |
| Med | Moderate | Balanced play |
| Hi | Fast | Score attack, experienced players |
The game also accelerates capsule fall speed naturally as you clear viruses within a level, independent of your chosen setting — the final few viruses of any round fall noticeably faster than the first.
Hidden Speed: “Super Hi” Trick
On the configuration screen, highlight the Hi speed option, then hold A + B simultaneously and press Start. On verified NES hardware and most accurate emulators, this launches the game at a speed noticeably faster than standard Hi — sometimes called “Super Hi” or “Hyper” by speedrunners. Capsules drop at near-instant speed, leaving almost no reaction time. This setting is not displayed on screen; the menu still reads “Hi.”
Two-Player Versus Mode
From the title screen, select 2 Players before pressing Start. Both players play simultaneously on split screens. The competitive mechanic: clearing two or more rows of viruses in a single chain sends extra capsules onto your opponent’s board.
| Rows Cleared | Garbage Capsules Sent |
|---|---|
| 2 rows simultaneously | 1 garbage capsule |
| 3 rows simultaneously | 2 garbage capsules |
| 4 rows simultaneously | 4 garbage capsules |
Garbage capsules are half-colored and pre-placed near the top of the opponent’s bottle, disrupting their current setup.
Scoring System and Combo Mechanics
Dr. Mario has no password system and no lives — it is purely score-based. Understanding the scoring helps maximize points for high-score runs:
| Action | Points |
|---|---|
| Destroy 1 virus | 100 × current level multiplier |
| Destroy viruses via capsule fall (combo) | Multiplied per consecutive chain |
| Clearing all viruses | Bonus based on speed and level |
Chain reactions (where a capsule half falls after clearing and destroys additional viruses) multiply point values significantly. On level 20 Hi speed, skilled players target specific chain setups that can clear 6–8 viruses in a single drop.
Bottle Opening Easter Egg
After clearing all viruses on any level, Dr. Mario runs to the medicine bottle and opens it. The viruses inside perform a short celebratory animation before the next level loads. On levels 10 and 20, the animation is extended with additional characters appearing — this is purely cosmetic but serves as a milestone marker for players tracking progress.
Score Cap Behavior
The NES version’s score display holds six digits, capping at 999,999 before rolling back to 000,000. Unlike some NES titles, this rollover does not crash the game or corrupt save data — play continues normally. Competitive players competing on leaderboards note the exact rollover point and continue counting mentally from zero.
Demo Screen Manipulation
If you leave the title screen idle, the game plays an automated demo. Pressing A or B during the demo immediately returns you to the title screen. Pressing Start during the demo drops you into a live game at the demo’s current state — the board, virus layout, and in-progress capsule all carry over. This is not a useful exploit for normal play but is a known behavior on original hardware.
Beneficial Glitches
Capsule Clip: On very rare occasions when a capsule lands and immediately splits due to a cleared row below it, the remaining half-capsule can register as landing in a column it visually did not enter. This is more reliably reproducible on older NES hardware with worn cartridge contacts than on clean hardware or accurate emulators like Mesen.
Pause Buffer: Pressing Start to pause at the exact frame a capsule locks in place can allow you an extra moment to visually plan your next placement. The game accepts the pause input after the lock animation begins but before the next capsule spawns, giving experienced players a legal reaction window during Hi speed play.
CPU Opponent Behavior (2-Player vs. CPU)
In Game B (single-player vs. the CPU), the CPU follows a deterministic placement algorithm based on color matching — it always targets its lowest-hanging virus of a matching color. Exploiting this: placing capsules that create two simultaneous matching opportunities forces the CPU into a suboptimal choice, often allowing you to clear faster and send more garbage before it can recover.
Version Notes
The NES cartridge (1990) and the later Game Boy version share core mechanics but differ in speed feel due to the different display refresh rates. Codes and tricks listed here apply to the NES version specifically. The Game Boy release has its own separate configuration options and does not support the A+B Super Hi speed trick.