Skills/Equipments End Game Question (potential minor spoiler)

[Hawk X]

I am at the end game when I have a choice at a computer, yet I am still missing 1 skill in the pause menu... the one at the complete right is the amount of shields, the one right next to it is still (?)... I have done every room and every secrets, got over 1.1M junk, 1.3M money, every store items from every store...

Also, does anyone know what the 3rd one from the right is? it has a robot with 4 arrows pointing to it with a number (3) in my case... cant figure out what that one is either :)

Finally, bonus question, what did collecting all the letters do? I "think" i got them all, but didnt notice anything special...

[Dreaded Walrus]

The item next to the number of shields can be bought from (one of?) the in-game shops. It's an optional item that just makes traversing the world less time-consuming when you're backtracking through the world in the end game, and even lets you skip certain hazards if you use it cleverly. It's the ninja suit.

The item with the arrows is the vacuum/magnet upgrades you bought, that suck nearby items towards you. The number indicates the number of upgrades you bought, and thus the strength of the vacuum/magnet.

I didn't collect all the letters, but as you seem to have missed what they do by themselves, each one unlocks a new "title screen". You can press the bumpers (or equivalent - I know that Z works on the keyboard, but I can't find the other bumper equivalent, if there is one) to cycle through different screens. Each one references some old retro game, some more obscure than others - I don't get all the references. It's a pretty cool reward in my opinion.

[Hawk X]

oh wow thank you so much for all of these answers!!! :D

I didnt expect such a complete and perfect reply so fast!

I'll have to do one last sweep of the shops it seems before i call it quits :)

As for the cycle through screens, I did found that out, just never figured out it was because of the letters :) (And im still unsure if i missed any even though i did all the rooms and all the ? secret rooms) -- I think the letters spell the name of the game, and if that is the case, i just checked and i did get many new page... and the exact number of letters in the game name... so it seems i got them all after all :)

WOW this game was so amazing... I have never played a game with such expectations (none really) and being completely blown away by the quality... I get why it got such amazing reviews! :)