First of all I haven't submitted any run yet but I made a mistake by not reading the whole rules. I'd like to know some opinions about my run, if it's worth submitting or not.

• I ran on Winkawaks, apart from turning off the scan lines and remap the buttons to my controller and I left everything on default.
• I added a ton of credits because I'm not a good player, there are 29 continues on my run.
• I ran the game on Arcade so I don't know which difficulty I was playing on. Is there a way to know? I have no idea how to tell the difficulty I played.
• I started the timer when I pressed the start button at the game menu, before the tutorial and player select. My timer is 10.600 seconds when my character lands on the water.
• I stopped the timer when the victory music finished and the screen went black; according to my LiveSplit the last hit on Rootmars is at 58m 54s 050ms (I stream at 30 fps so that is as accurate as I can go).
• Due to my inability of reading the rules I'm not sure how to time my run but if I had to take a guess I'd take 10.600 off of the 58:54.050 for a 58m 43s 450ms of playtime.
• I lost a lot of frames during the 3 Balls Fight before infiltrating on the Spaceship.
• I have no idea what is overclocking but I checked after the run and there's an option named "Configure 68000 frequency". I didn't move that thing before but it says "1 MHz", not "64MHz" as rules say.

One good thing is that at least I made my own input display and during the whole run you can see how I smashed the A button like no tomorrow.

I'd like to post my first MS3 speedrun but I'm afraid of getting rejected; after all I said, does it worth posting? And by the way I have no problem on run it again, so if is just easier to re-do the whole thing, then I'm ok with that and I will re-do it.

I don’t run the same version as you, so I can’t help for all. However I don’t think the amount of credits used matters, didn’t for me. Time does start when you touch the water on mission 1. As for the difficulty, knowing it is pretty essential due to the categories, however I can’t help there due to the version difference.

If you didn't mess with any dipswitch settings on your emulator it'll be Medium/Level-4 difficulty by default

So I think is better to re-do the run, check every single detail and make sure everything is fine. I don't want to risk a rejection and lose the privilege of submitting runs in the future. I'll try to check which difficulty I'll be playing on. The thing is that I played the game multiple times before but I never thought about speedrunning it until these recent weeks. All the times I played before on EMU I just chose Arcade, add a bunch of credits and I simply let the game be. I didn't mess with dipswitch settings as @zantomun says and I think it makes sense that Medium/Level 4 is the default difficulty setting.

Just one thing, I used 1 MHz (the default) in the configure frequency. Is setting it up to 68 MHz fine and valid? I heard that helps to prevent lag.

EDIT: I made a typo saying 68 MHz, but I won't delete it or change it just in case anybody has the same question in the future @zantomun has the answer of 68 MHz

Overclocking to reduce lag is almost never allowed on boards as it gives an unfair advantage over hardware and other runners without the ability to use those settings

I made a typo @zantomun, the frequency thing and the menu in the Wikawaks say "Configure 68000 frequency" and the 68 stuck in my mind LOL. The rules directly say "Runs done on Winkawaks with overclocking set to 64MHz." My run is done on Winkawaks but with the default 1 MHz frequency and rules say that overclocking set to 64 MHz. I meant to say is: Is setting it up to 64MHz is fine and valid?

To find out which difficulty you are playing on, press the "Test Menu" key (Default key: F11), then go to “Setting Up The Soft DIP”. Then select "Slot1 Metal Slug 3". There, it should say something between LEVEL-1 and LEVEL-8. LEVEL-1 = easy LEVEL-4 = medium LEVEL-6 = hard LEVEL-8 = very hard

A bit lower in the same menu, there should be a line where it says "CREDIT/LEVEL". Set that to "ON/ON". Exit the Test Menu using the grenade button and navigating to "EXIT". Now when you play, it should display the difficulty and the amount of credits at the bottom of the screen. (This is not required, but appreciated.)

I suggest just doing another run with the correct timing. If you are using LiveSplit, there is an autospliter that will time the run for you. There is a guide on how to set it up in the resources Tab. Although if you just want to do one run it's probably not worth the trouble.

Set the overclocking to 64MHz, as it says in the rules.

Submit your run in the WinKawaks category (NOT the Arcade category).

Thanks for your reply, I already ran the run again and I will be looking for time improvements in the future.