This is the first idea to get out of your head. It's not really unfair at all. It's tightly designed, and it knows very well how to give you an "out" in a situation. Yes, the mousetrap like "Hit by one thing, and then another...and then another... and then DEATH!" situation happens, but it's generally due to the player being unobservant and rushing at a breakneck pace, without understanding the rules of the game.
It's all up to understanding. For example, you can kill a giant spider instantly by tossing a bomb into hiw web, before he notices you. Enemies overhead can be killed by shooting a grappling hook up. Hanging from a leg and falling is the safest way to descend without a rope. Holding up or down will allow you to pan the camera, to "look before you leap". Arrows from Tiki-heads can be set off by dropping any object in front of them. You can use Rocks, Skeletons, or the mice in the cave for this. There is ALWAYS something on your path to use to set off a trap like these; if you don't want to look for it, use a bomb, or rope.
There's nothing wrong with the Whip hitbox. It even can be used to hit over your head or behind you. Weapons are very fun to use when you get them, but they aren't integral to survival; Though there are many who will P.O. the shopkeepers, so they can get that shotgun. (Even though this is a much-recommended strat, I rarely do it on purpose, personally.)
The main point of the game is to complete it in 1 run. However, as you get deeper in , Tunnelman will ask for items to build you shortcuts. They allow you to skip to any zone (Ice caves, jungle, etc) and start from there, without having to pass the previous stages. It's a great way to practice. Once you get good (not even great, just... know what you're doing), it's easy to clear the mines in ~5 minutes anyway.
In my time with this Spelunky between 3 systems, and watching my brother play, and he playing Co-Op with me, I can say I've seen much less "Random death mousetrap" than actual "Man, why didn't I notice that?!?" real deaths. Even annoying things like mines, spike pits, tikimen, etc, all have audible and visual tells. The late game stuff is much less forgiving, but you should pretty much be prepared to learn to deal with them, if you're good enough to make it that far.
Yup, totally something wrong! ;-)
Really, I understand the way of thinking, but I've never felt like my runs in Spelunky were determined fully by my luck. It offers so many things that overlap in usefulness (The treasure item gotten from the mines that points towards the exit and shows treasure, VS the compass you can buy that do the same thing, for example), that I always feel like I have a chance to get what I need, if I'm savvy.
Everything in the first 3 zones of the game CAN be navigated with just your default ability; having items makes it easier, and empowers you to avoid risk (why jump over the spike pits when you can just blow them up? Or tunnel under them!), but there's never a time when you flat out CAN'T make it.
And lastly, with all that said, it's probably much easier to learn the game with a co-op partner. If you die, you live buddies have a chance to find a coffin in the next stages. Break the coffin, and dead player is revived! Even when they're dead, their Ghost can move objects by blowing on them, or set off traps by moving near them.
Even if you don't have a live co-op player with you, just turn on controller 2, and carry the lifeless doll with you! You can toss them (or their dead body) into things, to kinda "feel out" the area, and rules (how close does one have to be for an enemy to proc, how far can one fall without taking damage, etc.)
