Poor Manky is absolutely desperate for the toilet, but some joker has walled it up! If he's going to get to the bog in time, along with the keys scattered around the screen he'll have to collect a quota of eggs which are laid by the roaming yellow bird that also consumes the piles of grain littered about the place - Manky himself has a violent and fatal reaction to the grain, although if he first chows down on an egg he can eat one pile. And of course there's an on-screen timer to worry about, if that expires it's quite literally brown trouser time.
What we've got here is a single screen platformer highly reminiscent of the early 1980's titles like Chuckie Egg, Hunchback or Manic Miner, which has been paired with a rather nonsensical story - all well and good of course since there are a plethora of great games that match that general description including the ones just listed, but not all is well in the world of Manky because it has a couple of major problems that only serve to gang up and prevent bowel evacuation.
THE GRAVITY OF THE SITUATION
The first of these issues is with the controls and in particular the jumping, because rather than utilising a conventional gravity-based jump as used in even the very earliest platformers or even a fixed speed rise and fall as employed by the Olli and Lissa series amongst others, pressing fire punches Manky into the air and, as he slowly descends to the ground, moving the joystick left or right will make him alternate between falling and moving horizontally, giving the appearance of walking down an invisible staircase - apart from looking bizarre, this makes nailing some of the trickier landings difficult and there are several of those since the keys have been awkwardly positioned.
Overall difficulty has been ramped to the max and that combines with the flawed jump mechanic to make even completing the first level an extremely frustrating task and just to add icing to the difficulty cake, the yellow bird that's meant to lay eggs will sometimes forget and make the level impossible within the time limit. The difficulty has presumably been set this high because there are only a rather stingy three levels included, but artificially extending the playing time in such an annoying way is a cheap design choice. Even ignoring the excellent platform games released over the last couple of years on other 8-bits, C64 titles like Joe Gunn or Knight 'n' Grail have set the quality bar extremely high and Manky is struggling to even clear hurdles.