This is NES "Low %" Metroid, which beats the game collecting only the morph ball. The submission improves the published run by 36.7s (2204 frames) using a new route and better optimized platforming, boss fighting and lag reduction.

Well, I meant to do this run shortly after I finished the 100%, but got busy/lazy. Sgrunt's submission got me off my butt -- thanks. I knew it could be improved using a different route, though prior to starting I estimated the improvement at only 10-15s.

Here's a summary of where time was saved compared to the published run. In summary, most time is saved by general optimizations. The new route loses 1 second getting to Kraid and 2 seconds fighting Kraid (no missiles), but saves many more seconds later due to the availability of missiles in Norfair and Ridley's areas.

Note that since different routes are used, I compare using the total time spent in each area, rather than in strict sequential fashion. The various areas are listed in the order they're first visited in my run. The times listed here are close, but not necessarily exact.

The key to the route is to sacrifice some time to kill Kraid first. This gets Samus a hefty stock of missiles, which makes the loooooong journey to Ridley, and the Ridley fight itself, much faster. The 2 main reasons are that missiles can kill at a distance, and can kill any non-boss/invincible creature in 1 hit. The former gives more options for refill collection and lag reduction. The latter lets Samus take shorter paths, with less lag because she can blast her way through just about anything. This is especially true in Ridley's lair, where in the 2 previous runs Samus is all but helpless -- unable to take damage, unable to kill anything -- and ends up losing a lot of time dodging enemies, not to mention lag.

The rest of the improvement was just optimization -- minimizing jumps and stops, maximizing damage boosts and luck manipulation. To avoid endless explanation, a lot of the tricks of the game are already described at the Metroid Tricks Page, the Metroid Any% run, and the Metroid 100% run.

One new discovery I found making this run was that vertical climbs are infinitely less tedious if you just focus on the small jumps where Samus must cross a significant horizontal span. The key is to hit the previous platform close enough to the edge (actually, off the edge) that the jump button can be held for 1 fewer frame. For all other jumps, apart from killing enemies and getting drops if they're needed, it doesn't really matter what Samus does.

Thanks to Sgrunt for describing a technique for manipulating monster appearance of which I wasn't aware -- having a dead monster leave an uncollected drop when the next screen is loaded is the same as having the monster still alive. This was very valuable to know in several rooms throughout the run.

I highlight many other interesting strategies in the subtitles, which is hopefully a more accessible way for people to understand what's going on than describing them at length here. I hope the encoders will include them if possible. If you find the subtitles distracting, you can always shut them off.

Nach: Accepting as excellent improvement to existing run. May I also say that this run is very nicely optimized, with high attention paid to every detail.