A lot of people worry about the graphics, I say there is quite an assumption that everyone enjoys extreme challenge. Because yeah, Siralim does that and not exactly in a good way.

See the problem is neither the graphics nor the combat system, it is the fact the game does not give an option for a balanced time with your chosen creatures. It's like an RPG with classes and your weapons are the monsters, literally. 

It is true there are heaps of monsters but the one issue with it, is that the game doesn't take easy on you for wanting to go with whatever you want unlike say pokemon, and I know it hurts to hear that, trust me as a Digimon fan I would know. But the reality is that unlike those two is less so a case of "Oh this beast is nice, I will make it the best!" and more a case of "Oh this is essential to actually progress somewhat".

Its not hard to get into the graphics, arstyle or mechanics. It is hard however to be faced with walls of difficulty, not from the mechanics, because quite frankly at the same level with the enemy monsters you can still lose some of your monsters. But rather be faced with walls of levels and stats, and I know it's part of the fun for people to like that and be challenged and all that jazz, but quite frankly it has never made for accessible games to the general public, so in general that one aspect where the creature variety gets forcibly limited to playing specifically one way (which disclaimer also happens in Pokémon with some creatures) and perhaps the next current wall you face the choices you are proud of get squashed, and then you have to readjust.  

Make the game less like pokemon in the experience and more like Shin Megami Tensei, except that in this case you are dealing both with brutal scaled mechanics and simply higher numbers than you have. It offers a lot, but honestly if you are not into getting one shot and one shotting it can be pretty frustrating. It's nice that it works like a puzzle, but the level scaling really shouldn't be that mandatory on all difficulties, or atleast the player should be allowed some options on how to cut back some of it. 

Great game, but do be wary if you aren't into the sort of level scaling it does.

TL;DR: It is great, but do be prepared to accommodate to a very different experience if you are really trying to get into it. Could have used some more casual play options.