Every time I see a replica cabinet at an arcade show it's the same thing - the "enthusiasts" thumbing their noses at it, saying it plays bad, or dismissing it after a couple minutes.
The key to this game is understanding how the control input works. Each press of the joystick = 1 directional movement, it's not meant to be held down. Additionally there are "left" and "right" sides to each ledge. Felix will always stand on the opposite side of the ledge from the direction he is traveling, to allow him to swing his hammer and fix the damaged window.
That means if he is standing on the left side of the ledge and RIGHT is pressed, he will dash one ledge to the right, but remain on the left side.
If LEFT is then pressed, he will make a small hop to the ledge to his left, and stop there, as it is now on the side opposite to the direction he is facing, allowing him to swing his hammer in front of him to fix the window.
Left / right positioning, and understanding how to manipulate Felix to get him right where you want him, is a key to advancing in the game.
The Jump button only comes into play when clusters of brick collect on the ledges in later stages, as it is used to clear them. The Jump button must be pushed at the same time the left or right movement is executed. This does catch a lot of people out and in my opinion is the only rough spot in the game's design.
A ledge with a cluster of brick on either side cannot be jumped to from the side, instead it must be approached either from the top or bottom (neither will hurt Felix, he will stand on the cluster without getting hurt as long as his approach and departure is vertically) or while invulnerable from a pie power-up.
And yes, the game does get very challenging a dozen or so stages in as the amount of hazards and movement restrictions from planter boxes really ramps up. It's like I, Robot - if someone who knows what they're doing explains in person how to play the game, you'll probably love it, but otherwise you'll just get bored or frustrated and step away.
http://dragonking.arcadecontrols.com...age=AboutIFIFJ
Beat to snot, empty, damaged Nintendo cabs are a dime a dozen. Every person I know who has built a Fix It Felix, Jr. cabinet has taken a completely converted or beat to hell Nintendo cabinet and given it a new lease on life and then handsomely sunk it into their Ninty row as FIFJ.