Well the achievement isn't really that difficult but if you are having trouble with one of the games, maybe this could help you.
Note: you do need to get THE high score not just on the list of high scores as some have pointed out.
On consumo hang near the middle of the circle so you can see the blowfish and avoid them while grabbing all the healthy foods. Also avoid the other sumos because they bounce you around and it disables your control for a little bit making it impossible to dodge anything in your path. This game takes a bit of patience so as long as you don't get too greedy you should be able to get the high score and you can just blow the rest of your lives after you have 1010lbs.
In nut shots you are a flying squirrel that shoots an unlimited supply of nuts. It also has no point lose for missing shots, so the advice is to constantly be shooting the nuts.
Killing 10 hornets (250 points each) will spawn a bat (500 points each), if you kill 3 bats an eagle (1000 points each) is spawned. Each cycle is about 10,000 so killing 7 eagles will get you more than enough for the 69,900 highscore.
Don't run into the enemies you have already shot that are falling down the screen as they will kill you as well.
The hornets shoot a single shot at you in a straight line, so it isn't a problem to dodge it. The bats have a crescent shaped attack that expands vertically so move forward to dodge the attack. The eagle shoots a "heat-seeking" salmon at you so move up or down quickly to avoid the attack.
In Monkey Fling you are a monkey that throws poop at spiders that are trying to make it to the groun from the trees and kill you. You also need to hit the bananas to make them drop to replenish your poop.
What I did for this game was stick to cover only the left side of the screen start to move right and shoot when you are under the bananas to knock them lose, then head back to the left side of the screen. Shoot spiders you see on the left half of the screen.
If a spider falls on the right side of the screen you don't need to worry about it because they won't crawl across the whole floor before they disappear.
When the bananas hit the ground start to move back to the right constantly shooting your poop (since you will be passing over the bananas you previously dropped you won't have to worry about running out of poop). Doing this will allow you to hit any spiders and the bananas that will appear after you pick up the ones on the ground. Rinse and repeat.
You should be able to reach the score of 333 for the high score fairly easily this way. if you have remaining lives you can just waste them, or see how good you are :)
Hope this helps.