When guessing between 1-100000 just pick a random multiple of 10000 such as 60000 or 40000 and adjust you first digit until you find out which two multiples it is between (eg. try 60000, if it says too high, try 50000 if it says too low, start trying between 50 and 60 thousand). Once you find which multiples of 10000 it is between, start trying the find the second digit (eg. if you found out the number is between 50 and 60 thousand, try 54000, if it says too low try 550000, and go up until it says too high and you now know which second digits it is in between. Keep repeating the process until you get down to the very last digit. (eg. 50000= too high, 40000 = too low. 45000 = too high, 44000 = too low. 44500 = too low, 44600 = too high. 44560 = too low, 44570 = too high. 44568 = too high, 44567 = your number.)
If you're having trouble beating it in 240 seconds, just do what I did. Play through it a few times not worrying about times. Figure out all the achievements and try to memorize all the ones the involve your keyboard (i.e contra, colours, programmers credit) and slight movements (i.e move left, move right, jump for 10 seconds). Then make sure you remember to click quality and sound, and hover over the hints. Remember to scroll through the achievements list. If you can manage to do all of these really quickly then you can use the rest of your time to do the slightly harder achievements (i.e falling from top to bottom, dying 100 times, and 101 times). + this comments if you found it helpful, and you think other people may find it helpful.
To get impossible right click then move off the screen. When it comes to green (green cannon, and snake) move back into the square and dodge them (very easy). When snake disappears, right click and move off screen again until the end. + If it helped.