Games that didn't scroll smoothly - why not?
 

Hello,

One thing has always interested me is that there is a great deal of difference in frame rates in Amiga games and I always wanted to know what factors or decisions dictated what the frame rate of a game would be. I always thought there was no excuse for jerky scrolling when the Amiga has hardware scrolling but then I suppose it comes down to whether you can get your game loop running in one frame doesn't it? Forgive my noobiness but is the general rule smooth scrolling == running in one frame and jerky scrolling == not running in one frame? Or was there more to it than that?

Some games I consider jerky (from memory):
- Gods (and most bitmap brothers games)
- Flood
- Ruff'n'Tumble

Some games I consider smooth scrollers:
- the Turrican games
- Soccer kid
- Toki
- Battle squadron

These are my assumptions about why some games were silky smooth and some were a more jerky experience:

Coder
Obviously, some coders are more talented than others, so will get a game running nice and smooth where others may have failed.

Design choice
Some coders may decide they want to achieve something they could not do in one frame, ie increase the number of sprites/particles on the screen but at the cost of framerate.

Laziness
Some coders probably didn't care if their game scrolled smoothly or not? Why worry about optimising code when you can just run in 2/3 frames?

Portability
I always wondered if the reason some games were jerky scrollers was something to do with portability? Was it easier to write cross platform code without having to worry about scrolling smoothly?

Another thought I had was how possible would it be to take a game with jerky scrolling and get it running smoothly? Is this a impossible task? Say, for example, you took a game designed to run on a 68000 and ran it on a 68030 could you get it running in one frame? Surely, you are going to have a lot more clock cycles spare at each vblank so isn't it possible?

I'm probably missing the point here so I would love to be corrected on all the wrong assumptions I have made. :)

Mostly it was laziness, a hell of a lot of the early Amiga stuff was ported from Atari ST code, and the programmers pretty much just made it run on Amiga and did virtually nothing to enhance it.

Sometimes it was because they didn't want the game dropping a frame. A lot of the Bitmap Brothers stuff is done so that the game is supposed to run at a set rate no matter what is on screen. The Bitmaps generally have a lot of stuff going onscreen, which if it ran in 50 frames, would probably slow down and go jerky anytime something big happened onscreen.

Time constraints on a lot of people put them off bothering. If US Gold accepted that the game wasn't going to scroll smoothly, why bother to put the extra effort in? A lot of developers were paid a set price for the game they were converting, so there simply was no incentive to put more effort into it.

And some programmers simply were not very good at all.

Look at the learning curve of David J Broadhurst. Early games like Ghouls n Ghosts to later stuff like Assassin, shows just how bad a programmer he was to start with, and got progressively better.

Is this really the reason why they used mostly 25 FPS in their games? There isn't too much action i.e. in Gods. Ruff'n Tumble in 25 FPS makes more sense, there is a lot of action. But Core Designs Wolfchild used it too. It doesn't look soo fastidious, technically.

Superfrog was the smoothest of all IMO.

As for the bad ones, I also remember Shinobi and UN Squadron (the game would turn into slow motion when there were too many planes on the screen.

Amiga Rolling Thunder have ultra jerky scroll and animation.

A bad arcade to Amiga port, nothing special. ;)

first games that comes to memory that had great scrolling are Wiz 'n' Liz and Globdule. but those too, at least on Winuae aren't save from very casual bumps, i would think hat there is a cpu/memory usage soil after which things gets difficul to manage smoothly

Thats the reason for The Bitmap Brothers, and in Gods there is quite a bit going on, sometimes upto 12+ enemies onscreen, plus the destruction sequences for killed enemies was quite large, plus any animated items within the game.

Mmh, there are probably some smooth scrolling Amiga shmups with more sprite action. Anyway, 25 FPS aren't really enjoyable to play.

Bionic Commando and Barbarian (Psygnosis) have the worst scrolling IMHO :-) which is unfortunate as they are good games in most other respects...

A useful enhancement that could be made to jerky games would be to smooth out their lame scrolling. Rather non-trivial to do though if you have to start from a disassembly of the relevant game.

Baby Jo !!! :bash
Probably the jerkiest game I've ever seen.

Quadralien is pretty jerky.

I remember Vixen on the ST was jerky, and assume it was the same on Amiga.

Yep, the same eye torturing shit. Just like Ghost'n Goblins, Wonder Boy in Monsterland, Castlevania... :sad

Kid chaos has a great scrolling.

hmm.. i have to say, if you cant see past a bit of imperfect scrolling, or even graphics which arent the best, and instead look to the gameplay, why bother playing retro games at all?


Xenon II is one of my favourite shooters of all time, yet i hear the scrolling bitched about all the time. personally i couldnt give a toss when the game is that good.

A smooth scrolling is an important thing for a good playablity, just like the controls. Xenon II is not more than a mediocre shooter with a nice presentation.

Battle Squadron or Hybris are good vertical miggy shooters, technically and in the playabilty aspect.

we'll have to agree to disagree i'm afraid. I'm not keen on either of those, and i cant fault the way Xenon II plays, and it is far from mediocre in my opinion.

I agree, playability is the reason to play games but maybe it's a programmer thing but when I see a game which could have been implemented better technically I can find it a little frustrating. It doesn't make a rubbish game better or a great game necessarily more great if it has smooth scrolling instead of jerky but I find it makes the whole experience of playing the game a bit nicer.

so as a (recreational) programmer myself, what's my excuse? ;) :laughing


nah, i do admit, obviously when things are done right you do take notice, but i think a bigger deal is made over most of these sorts of things (scrolling, graphical or musical style etc) than often needs to be.

A game can look dated, feature music you end up turning off, and be far technically brilliant, but can still be very very enjoyable if the gameplay is good. (wont mention my obvious example of this)

i thought most retro-gamers were of similar thinking... but it seems not. :crazy

many games for me like that Ruff'n'Tumble game were / are unplayable to me due to choppy scrolling that makes me so nauseous that I need a bucket to vomit in like I'm sea-sick, regardless of any other accomplishment of the game.

It is a major turnoff, choppy scrolling - along with slowdowns.