In the areas where the black holes quickly open up to swallow you just simply pause the game and unpause. When you return to game play the holes will be frozen in the state of expansion they were in when you paused. They will be invisible but smaller. Simply side step around where you saw them last and you will be in the clear.
When fighting the Bull-Tank you can reset its position by accessing your Sub-menu. This comes in handy if it gets too close, due to it having a 1-touch kill on you. To defeat it, use your Grenade Launcher.
Enter the following at the password screen...
When you escape the Final Level have your character smoke a cigarette and the time will be reset!
When entering the Super Computer's room, stay in the door frame and push right on the control pad. You'll automatically warp to the final boss and won't have to worry about the base's self-destruc countdown that the computer's destruction usually starts. Now you have all the time you need to beat the last boss.