I tried an evasion archer and it just didn't work at all because the hits that do get through hit way to hard.
This is a really horrible mechanic for this exact reason. It makes gameplay much more luck based. Even if you evade 99% of the attacks, the 1% that land are an instakill.
Also there are strange difficulty spikes throughout the game. The first 3 acts are largely easy. It's very rare I ever had to go back and level to go forward. The final boss in act 3 (let alone act 4) is so vastly higher tier than the rest of the game, it's laughable.
The entirety of Act 4 feels like they spiked the difficulty up a level. I was playing a marauder (a dps marauder) and it took me a LONG time to beat the final boss. I'd walk in, land 2 hits and then instakill. I could surmise I didn't level effectively, but this was so late-game I had no chance. I absolutely HATE games that have difficulty spikes (That's one of my biggest negatives for Psychonauts, a typically great game).
The biggest problem with the game however is a similar problem to Diablo, its loot. I don't know why these games do this, but loot will drop for stats you'll never have. I can't tell you how many times I'd beat an act boss and an intelligence item would drop (again, a marauder). This system just feels lazy, especially on a final boss. Seriously, I beat the act 4 boss and my reward was a pair of rare boots...are you fucking kidding me? I understand farming and it does have its place, but you shouldn't need to farm for hours to get a good piece of gear...the game shouldn't lag behind for that long.
I think the easiest ways to improve the game would be:
Either make drops class-specific, or increase legendary drop rates. It may make gameplay shorter, but it makes a lot of the game less pointless. RNG to this scale is like Mafia II's open world, there's plenty to see, but little of it is useful to you.
Even up difficulty game-wide. You can switch difficulties but there shouldn't be that big a spike during one playthrough. Even those that level correctly agree Act 4 is far more difficult than the rest of the game, even scaled for difficulty.
I know this is a free-to-play, but that's no excuse for unrefined gameplay.