Although a leaderboard hasn't existed for this game until 2021, I recently came across an old player named Tank765k, who has uploaded videos (some with multiple Maps in one video, which will have to go for all the levels in those ones) of completing all 32 levels back in 2014! Some of them are still WRs today, and I doubt speedrunning was even the goal!
See if you can find any other old WRs that complete the maps faster- and try to learn from them.
If it isn't a WR, and wasn't an attempt at a run (doesn't have a listed time), don't bother putting it up.
The ones that are playthroughs but not runs will be easy to beat.
Map 16:
If you're looking for a run on Military Madness (which is different), Ace1000Ks1975 has a sub-hour run on Map 16. It's not nearly as fast as the Nectaris run, but it beats the current posted WR- and isn't even classified as a speedrun attempt. If you're starting the time from the second the player gains control, I calculate it as a 57:15, which beats the current MaxisMozark PB by 20 minutes- and it's from 5 years earlier (2016). Keep searching the internet for more playthroughs that beat posted WRs.
The difference is, Military Madness is easy mode. You are more damaging and more accurate. I've now beaten Map 16 in both games as of today, and the difference is staggering. Nectaris is far more of a struggle.
