to add in to Xiaou2's post, there are about 20 high quality light gun games out there that can be played on PC, in order from best to worst they are
Time Crisis 1
Time Crisis II
Time Crisis 3
Time Crisis 3: Rescue Mission: - lasts 20 minutes so a game in it's on right.
Time Crisis 1: Special - about 15 minutes long.
The House of the Dead 2
The House of the Dead 1
Crisis Zone
Confidential Mission
The House of The Dead - Overkill
Time Crisis - Project Titan
Ghost Squad
Vampire Night
The House of The Dead III
The Lost World
Ninja Assault
The Maze of the Kings
Virtua Cop 1
Virtua Cop 2
Silent Hill - although this game may be considered to be quite poor.
Time Crisis 4 - actually need a ps3 and use guncon 3
as far as difficulty is concerned, sadly that is an issue with all these games, there is no modern checkpoint system, I tried to think of putting a checkpoint system in place via save states, but it just got too complicated to implement, the only thing you could strive for is seeing how far you can get on a certain amount of credits, sadly at whatever point you run out of credits you'd have to play through the game again from the start, but it's the best that can be done at the moment.
what would have been awesome is if they made it that in some sections of time crisis, if you shot 8 enemies in a row without missing it would grant you an extra live, and you would survive through the game like that, sadly that's not in effect.
and on the topic of recoil, i would advise you to read over this thread, where someone managed to use an arcade gun just like the namco guns and put an aimtrack in it.
http://forum.arcadecontrols.com/index.php/topic,119610.240.htmlI am currently trying to do the same thing, but I am stuck trying to make it.
Would that wide angle lens trick work with aimtrak, as currently I have to sit 45" away from the screen, I would like to be much closer.
actually Xiaou2 time crisis 5 uses 'internal' recoil now as well, I think you could get the same amount of power from internal recoil, the sliding mechanism is more for looks, but in the case of the ultimarc recoil kit, that kit itself may not be that great, I would not know, but i believe its immaterial whether the gun kicks back or not, that was mentioned in the thread I linked.
also as I said in that thread arcadeguns are upgrading their guns to allow for a recoil system, both USB and mains powered, more details are in that thread, looks like they are selling the guns now and in black, but we will have to wait until the recoil kit is provided, but to my limited knowledge it appears there is not very much space left in the gun to fit a decent sized recoil, you can see how much space there is by the gun product page, it may end up being just like ultimarcs recoil kit, perhaps even worse, time will tell.