Seems like a pretty nice concept, despite a few minor hiccups.

No real story yet, but a nice foundation to lay out one. Still, a little bit early to say anything about that.

Certainly have enough variety to try different things.

Graphically wise, it's not eye straining, excepr for a few minor interface annoyances, like stumbling to a boss that heals faster then you damage it, which leads to interface always jumping, since it health bar when full shows just a simple number, but when damage it divides to current health/full health, later on more often then not goinf to a pair of lines. And so, cycle of damaging/ heaing leads to extremly irritating screen jumping. So be aware of that.

Also, maybe font size might be also added to options, as a suggestion.