Sandbag for horror verse?

I’m at lvl 20 currently. Do the levels get harder that you need to grind to get a lot of upgrades to get through them? Should I stay at a lower level and die at the end to get enough for upgrades before advancing? Or can you get through them based on how lucky you get with skill choices?

I haven’t been able to get lvl 2 of additional projectile upgrade yet. Also, does anyone else find that the higher level they go, the worse skill choice gets? The additional projectiles and Molotov skills are a lot rarer now it seems.