Was very disappointed by it. The game looks good with a similar hades tone, and the combat works well, as well as has some interesting and tough boss fights. You can save and quit during runs which should be a necessity in roguelikes. Then there's the negatives......
First off you can't change controls. Also as people have said, theres only like 3-4 enemies you fight through the first 75% of the game. Hours in a few more enemies pop up, but its nowhere near enough. All the enviroments look identical, that with the enemies makes the game too shallow and repetitive. The upgrades can sometimes come together to make fun builds, but most of them aren't that interesting. There also aren't enough, leading to you getting and using mostly the same ones every run. Then theres the weapon. You use a javelin and punches, and thats it...... You unlock different effects of the javelin, but theres only 4 total to choose from by the end of the game. Even when you get others they have the same main effect but with slight mods on them that don't make that big of a difference. The fact theres no other weapons to unlock is super lame and inexcusable, as even with the different effects it doesn't change your playstyle that much and still feels same. The heat meter is also annoying because all javelin effects use it. Also the bosses don't change with runs, as theres 3 total and you fight them in the same order. You have to beat 6 runs for some reason to beat the game but all that does it make you fight second phases of the SAME bosses. Also during combat with the flashy animations being so visually loud its hard to tell if the enemy is attack or doing anything so many times you'll be hurt without realizing you were about to be attack or were being shot at which feels cheap.

So only being able to use a single weapon, with a total of 4 effects unlocked throughout the entire game. 3-4 enemies most of the game, the same 2-3 bosses, the same mostly-uninteresting upgrades, on the identical levels, this game just feels like a grind and bore with minimal payoff. Its not terrible but they could have done much more, it has almost none of the foundation needed for a rogue-like game where you are fiending for "one more run".

6/10.

I am actually surprised this game did so poorly. On the surface it competes immediately with Supergiants games to the point of almost feeling like a straight offspin. The combat itself is, in my opinion, much more interesting than Hades on top of feeling snappier as well. The visual style is extremely derivative of Supergiants' work as well, albeit infused with a lot of punk elements (as should be obvious from the screenshots). Awful use of color palettes aside (which I will get to) Reign Breaker radiates quality.

On the most base level the idea behind Reign Breaker is sound: you alternate between your fists and your javalin. The latter operates on a resource but allows you access to ranged attacks or powerful special attacks. This feels like cheating and trivializes the game, but due to being generated by the first this should not matter. The game also offers glory kills to fully reset the resource entirely. Furthermore, the game actually has a rudimentary combo system (not the score counting) where attacking in a rhythmic way allows you to get access to special attack chains. The elements here make sense. They are generic in nature and allow for a lot of skill expression.

Unfortunately the game is another "roguelite", so the above is thrown out of the window immediately. The javalin is essentially the only thing you want to use ever and through upgrades this is easily achieved, essentially turning the character, once again, into a ranged and/or special spamming variant of themselves in a game that is clearly not designed around that.

There are a lot of tiny "how did that get past testing?"-moments such as enemies spawning a pool of damage substance right before entering their glory kill state, essentially making it impossible for the player to kill them before they self-revive without taking damage or upgrades that blatantly negate other ones (your typical "take no damage" or "be below x health", while others are "when taking damage" or "above x health"), but certainly not more than games like Hades or Hyper Light Drifter, which the game seems to be inspired by.

The main issue with Reign Breaker is the visual clarity. In-game it is not as bad as the screenshots will have you believe, as the game differentiates between things "animated" and "non animated" quite well, but it is still atrociously bad to the point of comedy. Very bold colors that are used entirely at random. Environment colors that overlap with projectile colors. Way too much visual clutter. It's bad to the point of almost feeling as if so to make a statement. I can't imagine you can scale the difficulty of this game up without the entire challenge just converging to trying to make any sense of the blur of colors on screen.

I don't think this is a bad game per se. It has a lot of issue, but so do games like Hades and they are still being praised into the high heavens. I am a little surprised how much dislike Reign Breaker has garnered considering how similar it is to other titles people run away with.

Very fun.