With Treasure Buster finally out, I gave it a shot.
It definitely plays like Monster Strike with Rougelike/RPG elements added to the mix.
Replay value may vary, but Endless Mode helps with this. There is also Arcade Mode with each of the game's six characters having their own set of stats (which you can increase after the end of each of the four out of stages), special abilities from the game's "Aura Meter", and their own endings. It may be repetitive in the long run, however.
I guess only real gripe is, while the game relies on skill and luck, you may eventually have to rely more on luck as the final two stages is occasionally, if not often, loaded with traps hazards that can possibly do more damage to you than the enemies themselves if you're not careful. There is, of course, a parry mechanic that blocks attacks if you tap the screen right as they come at you, so that can help. But it's never explained.
A fun game in its own right. Though, if nothing else, you should definitely get it for the kick-ass Sega Genesis-style soundtrack.