Is it the usual defeat rape/event collection game or there are some interesting mechanic like battle-rape or something?
It's the usual.
However, it's quite easy to lewd the main heroine which makes event collection rather painless. Art is good, events are decent so it's a good game for one playthrough (or one fap session if you prefer). Unless your internet is crap or your bandwidth is limited, it's worth downloading.
Honestly, even if this game is only decent, it's worth playing because dlsite is being flooded by clunky, buggy crap with AI generated art nowadays which makes this game great in comparison...