I think the "samey movesets" complaint of Nick Brawl is less a case of bad/lazy/inexperienced game design or even the lack of funding as much as it is a conflict of interest - people are going in expecting Namco-era Smash moveset design, heavily focused on surprising gimmicks and special move abilities never before seen, but NASB is more aiming for HAL-era Smash moveset design where attributes, stats, range, e.t.c are characters' main defining factors.
Not helping matters is that NASB doesn't have tripping, burial, freezing, e.t.c. (in fact next to no platfighters other than Smash do) and prefers to inject its Nicktoon wackiness through more subtle ways like RPS, projectile mechanics, and the breakneck speed/air dash.
Nick is not designed to be a solely competitive game, but it's also a game that seeks not to isolate competitive or otherwise devoted players - and there's absolutely things casual players love in Smash but competitive players loathe, which probably aren't gonna make it into Nick (or any platfighter really) as a result.
