Super Chicken Jumper

Enter passcode skull, sword, snake to use nuke cheat.

Note that when using cheat, no achievements unlock.

Start story mode and play up to level 6-2 using nuke. Just keep pressing X/RT to go through the levels. The only levels that my give some trouble:
3-6 & 4-6: These bosses, nuke doesn't work, so use the pistol & jetpack.
For 3-6, just hold down RT. If a vertical red beam shows up go towards the wolf and keep shooting. If wolf shoots projectiles forward without jumping up, jump over them as needed. If wolf jumps up, you can try to dodge but might be faster to kill yourself and try again.
For 4-6, just hold RT with RS pointed towards the face. If she extends her arms or arms come from ground jetpack over. If she transforms to the flying thing, jetpack over to the right, and then jetpack back over to the left.
For most of world 4, there are holes that shoot something out, when the nuke hits the ground you have invincibility window, so go over the hole just as nuke hits the ground for safety.

When you beat level 6-2, you will get a laser gun.

Now start endless mode with jetpack and laser gun on farm level. Jetpack over to the middle while charging the laser gun. Shoot. Repeat this over and over until 60 seconds.

Here's full walkthrough for 1000G detailing this method: