I enjoy the game and what it has currently. It is just getting so close to the highscore in the minigames and not beating them is agonizing.
I haven't finished this version yet, but it is fun so far. The only feedback I can give right now is the game has a lot of typos, misspellings, and or words that are out of place throughout the games dialogue. Some sentences don't make sense because of this, at least on the first read through. That and the fight against the Fallen Angel Kakodal or something at the school during the incident with the shards of Excalibur, the characters Kiba and Xenovia the wielder of Durandal don't seem to be able to attack. Even if the fight is rigged against the player they should be fixed.
So alongside the fights that aren't in the game yet that I want implemented and the fixes to some characters during fights, please give the game read through it's dialogue to find and fix the spelling and or grammatical errors.
As for ideas for scenes, maybe bring in the Highscool DXD anime series OVAs into the game. The anime had a lot of funny and exciting moments in the OVAs. If this game stays true to the series's storyline then introducing the OVA scenes shouldn't cause any conflict with the story. And there is that episode thirteen from season 3 of the anime where Ise goes to help that Phoenix guy he beat up to free Rias, it was that limited edition episode they bundled with the manga I think.
Also, what was the choice that was asked for to be in game?