It's a nice and easy game, can't complain about anything really. I'm happy that the 2 ice stages didn't include those sliding mechanics like many other games with ice stages do, I hate those.
What I noticed though is, that the 2nd boss is actually the hardest compared to the others.
The first only has one attack and just stands there, sliding down to the lower ground after some dmg and repeating its attack. I just spammed him, way to easy, even with the 2 turrets.
The third can be dodged easily in all but the last phase, which also only takes like 10 seconds to get used to.
The 4th had easy patterns, so generic in fact that I already forgot how exactly the fight went, lol.
Even the final boss was underwhelming, considering it's the final boss but has easy to avoid attacks and only does 1dmg with them, even though the player has a minimum of 7 hearts by then, if not probably full 10, + probably 3 health potions from the trader, with still a lot of cash left to buy more if it was possible.
Meanwhile the 2nd boss could do like 4dmg if I accidently touched him while attacking in midair, which could happen quite easily if I have to jump towards him to land a hit. The player has only about 5-6 health there, so the boss could almost 1-shot by just floating there while I try to hit him. Then he's invincible for like 30 seconds while I have to use the ladders to avoid him AND 2 projectiles that always spawn in the projectile-paths that I'm currently in, so I have to dodge a lot, on both axis, using ladders unlike with other bosses. It's the only boss where I died, with the others I could mostly stand in one spot and just jump to survive. They were almost laughable easy compared to him.
Also, why did I get the by far strongest sword at the end of the game AFTER basically everything (including the final boss) is done? It's like "Here is the best weapon in the game, you won't need it anymore though." I can see that it could be a help for those who have to revisit old stages for missed chests, etc., but the game really isn't hard and after the final boss it should be no problem to fully stock up on potions and bombs at the traders.
I hoped that huge dragon/shark thing on the map would be like a very hard extra stage, giving the last sword a reason to be unlocked, but apparently, even though it's actually an extra level, there are no enemies and no boss, just a treasure that I also won't need anymore since I got everything else (including the 999 cupons) throughout the maingame. After 1h of waiting for it, it wasn't worth it at all, a bit disappointing...
So in conclusion, if there are things to improve on (in my opinion), it would be:
-The bosses, adding more attack patterns and trying to make them gradually harder through the game (maybe adding endgame content, boss rematches, boss rush, secret end boss, etc.), also try to avoid fights where the player could stand on one spot and jump to avoid everything, that's too easy and not memorable.
-The unlock-times for certain items, ensuring that unlockables (especially the best weapon, etc.) don't turn out to be useless for 90% of players because everything is already done.
-And more content for possible extra stages, which are usually harder than the game.
Adding a level that unlocks after the endboss, that looks like a huge extra boss, or a dungeon, that does end up to be just a treasure room... could be quite a let down for some players that expected something epic there. Let downs influence the judgement of the game, try to avoid them.
The game has potential, I haven't played the first one yet but with a lot more story and without those "flaws" it could've been a much bigger hit back then.
But oh well, who knows if any of the developers will read this after all this time... but maybe others will, and find some kind of inspiration in this :)