I was invited to post a challenge of mine here (something that my interest for never exhausts) and here's one I've been spending the most time on lately.
I had a traumatic experience playing Digimon RPGs for the PS1 as a child, and ever since I've been looking for one that's not an eternal soul torture. I always enjoy the experience of Digital Card Battle, but among JRPGs, this one has to be the best one I've played (still need to try the DS games though). I even bought a PS4 so that I could play it (and Persona, and some other stuff too).
I suppose a No Digivolution run is a variant of the no experience Pokemon playthroughs I like doing in that your team keeps growing obsolete and you can't keep training the same mons and expect to succeed, so you have to catch, or in this case, scan new ones. Also, since you're unable to digivolve and de-digivolve back and forth like you would in a normal game, the level caps are much lower than they would be in a normal playthrough. I've never once had a Mega with a level cap of under 99 in a normal file, but they all cap at 60 on this run.
Since this gameplay here resembles Shin Megami Tensei's mechanics of "use buffs retard" with stackable buffs/debuffs (albeit with no press turn), with the Vaccine/Virus/Data triangle being incredibly dominant as a type advantage makes you doubly good at dealing AND taking damage, the Bug negative status being the only way to get around being at a type disadvantage. The common Eater enemies / bosses are outside the triangle and require other tactics than switching to a hard type-based counter.
The video I linked shows what is probably the most difficult battle in the run yet, as a full party of Vaccines couldn't handle Machinedramon's Infinity Cannon. Since it powers itself up before using it, it OHKOs in spite of the type advantage. I ended up using a Bug strategy against it because Data-types were far better equipped for survival against its attacks (the bulky Knightmons being lifesavers).
The game has two difficulty mods - Normal and Hard. The former is too easy, while the latter is notoriously unbalanced among its players. It's not uncommon for bosses in the second half of the game to get an obscene number of turns against your party and completely overpower you. So far all of my battles have been fought on Hard Mode, but I do not know if this can be carried on until the end of the game.
Check it out!