Hi all. Wanted to share my strat for getting the 100k and clear up a few things I've seen posted online about it.
If you just want a summary. Keep your score under 90k when you finish the first level to avoid the secret boss. Grab the machine gun in the first level and avoid the flamethrower. Grenade the helicopters and the body armor dude that shows up. You need to have 9 or 10 grenades to make the 1st level boss easy, not the 15+ I saw other people mention. I found running with Y better than rolling. LEARN THE ENEMY PATTERNS. For level 2, learn the patterns, grenade the crap out of the body armor dude with the female hostage. Once rescued she will shoot things by your side until you lose a life. Blow up the buildings if you need to for extra points and that should put you at 100k.
http://www.twitch.tv/bonkekook/v/825744293?sr=a&t=287sFirst, and this is the big one, how do you avoid the secret boss after level one? I went through both of the Xbox and Windows versions of the games today and I'm fairly confident I know the answer. So much so, that once I figured it out, I finished Hi Score 100k on the Xbox, and Hi Score 100k and Caravan 100k on the PC my first runs afterward. The timestamps on here prove it and you can check. They were all within 20 minutes of each other.
I'm still not very good at video editing, so I am posting my unedited Twitch stream(complete with 5 minutes of self-loathing for finally triggering the second level and accidentally pressing the back button to quit out). I'm hoping to fix my mouse and make the videos easier to watch within the next week or so, but this still functions for what you need to know.
0:00 - 3:08 was my first run. You can see that I kill the bosses within a second of each other(which was a proposed level 2 trigger) but still get taken to the secret boss. However, note that my score is over 90,000. I die, Rage, and restart.
3:09 - 6:15 is my second run. Again, I kill the bosses together within 3 seconds, but my score is below 90,000, and behold, I get the 2nd level instead of the Boss. And then I'm a complete idiot and hit the select button and screw my run over. I ran away to cry for about 5 minutes and then come back at 11:10.
11:10 - 14:30 Another decent run. Get to the bosses. Have over 90k, kill them pretty far apart and get sent to the secret boss.
14:30 - 17:55 Again, another run over 90k, get sent to the secret boss.
17:56 - 23:35 Crowning run. I again stayed under 90k, and went on to the second level instead of the secret boss. I actually got to 150k on this run so you could use it as a guide for the Original Mode, too.
A few more tips.
At 0:09, there is a dude I shoot in the back, left of the copter, who drops a machine gun. At 0:21/0:22 there is a guy in the top left who drops a flamethrower. The flamethrower ia effective, but the machine gun lasted longer so I started avoiding the flamethrower and could usually take out the first two boats with the machine gun. As you are going through, trh to avoid the 200/500/1000 point pickups. Its imperative to keep your score under 90k so you can reach the 2nd level and not the secret boss. Use grenades on the smaller choppers that attack you. Other guides recommended holding onto them, and I found it best to use them on the attack copters. Right after the group of 4 attack copters I sometimes used a grenade on the group of people. Its optional but I wanted to mention the opportunity. I also spammed 3 grenades on the body armor guy that shows up so I could focus on the other enemies. Right after him are 3 monoliths you can destroy for points. After these you get ambushed by 5 or so dudes and an attack chopper. Again, spam grenades. Having 7 grenades and all your lives is better than having 10 grenades because you died. At the boss, spam the grenades on the statue to take it down. It will drop 3 super powerful grenades. Use them and keep shooting the bosses to take them down quickly.
For level 2 your goal is to just stay alive long enough to reach 100k. Focus on killing the things that shoot back. Ignore cargo copters and trucks. About 15 seconds in, two body armor dudes show up ans one of them has a female hostage. Spam him with grenades to rescue her and she then joins you, shooting when you do until you lose a life. The next 30 seconds are crucial. There are 2 buildings to destroy and only regular enemies who are easy to kill. The buildings give 1000 and 5000 points, reapectively. After that you get attacked by cartwheeling red dudes and an attack chopper, followed by 2 body armor dudes and it gets hectic. There's also a 3rd building that also gives 5000k and that should put you over 100k, as I was at 125k here. You have a few more enemies to clean up before a miniboss shows up. I spam grenades, strafe and shoot until he's dead. That gives you another 20k.
Feel free to ask me any questions.