Yes fair enough it is sold on the same premise as pacman and yes it is similar but you show me a pacman game that isn't that similar!
In all honesty I believe a lot of work went into this game and also warblade (Which is a blatant rip-off of galaga!) and Edgar deserves some return on his time spent.
Nobody forces anyone to pay for his effort and maybe if nobody did pay he'd stop and maybe do something more original.
There are always going to be direct rip-offs of games and other media in the world, and others are going to make money off of it (Check out the ingame music in Tower of Souls, it was ripped dirtectly from Blood Money!), is there any point in complaining. Just boycott it if you don't like it!