Xerra's Blog

Drunken coder ramblings

The final gameplay element —

A dramatic title for this entry but probably a bit of an over-statement. Over the weekend I put a lot of time into Envahi again after my temporary switch back to Boulderdash to start work on the object system. I’ve got that working up to a point where I could test the enemies and, whilst improved, they still need some more work and I’m on a deadline, so it’s back onto the shelf until this game is done.

So we start with bug fixes:

The dam collision had stopped working due to something I had done or forgotten. I suspect I pushed delete by accident while the object was highlighted or something similar and never noticed until now.

I had more animation issues due to adding bits like new enemies since last testing pause and transition game scenes that needed fixing.


The UFO now spawns droppers going left to right like the original game. It doubles its speed coming back so it can make another pass. I thought the other way made more sense when I first put the UFO in but it really doesn’t so this was a quick fix to correct.

HUD panel is just an outline for the moment. I wasn’t happy with the original so something else will need to be done with this when I reach the tidying up stage of the game.

Background graphics have been edited to remove their old sky backgrounds from the converted photo’s. I ditched one that had a watermark on it that I still had in the game from the original images that I’d forgotten about. 2 new ones have been added but I will probably need one more as I need to ditch the night view city as it looks daft on a blue sky background. Tempted to also ditch another image that isn’t one of these city photographs as it also looks a bit out of place. Either that or I’ll just stick with the five cities I have. At present I still don’t actually know how I’m going to use these images – as in some kind of level change system or just have a random one each game.

Much work has gone into building a balanced level system based on Easy, Novice, Hard, Suicide now. The game is pretty tough even on Novice because the original game was quite tough and I wanted to keep that. I have a scoring adjustment system based on what level you’re playing so scoring is always fair, and I don’t need to have different high score tables this way. My thinking is on increasing the level of difficulty as the game progresses. At present the speeds based on level selected don’t change during the game which may mean games last too long and become boring. It’s not exactly a game with a lot of content so it would be better to make it a game that’s just played to get your best score possible and not take half a day of game-play before you eventually lose all your lives if you’re really good at it. As it is on Novice I can comfortably play a good 15 minute game even with the shields getting a hammering from acid rain pretty much constantly.

Other changes included making the collisions between player and the dam/buildings affect the shields on both elements. These are almost constantly being drained unless you’re really quick on the danger of the acid clouds now so sometimes you will be using the helicopter to actually absorb large patches of rain because you have more shield energy than the city and need to make that sacrifice so you stay playing a bit longer. This works really well and has changed the game dynamic to mean the clouds are now really number one kill priority when playing rather than the Zoomer, as you’ve got more time to deal with that. It makes the game play a bit better than the original now, I think. Up to the testers to confirm if that’s actually the case but the clouds are a much bigger threat now than the original game. There it only appeared in one place and was more of a annoyance than anything else because it was so damn hard to hit it without getting killed by one drop of its rain. Not great game-play that bit.

I’ve also made the grabber work a bit better now, and meaner, just for the hell of it. Now he does drop his base and roof when you shoot him too. Gone back to the original graphic I designed for him too but it’s still pretty poor. More on the sprites a bit later.

The dam has now been modified to have a single line of tiles as the wall as I’ve got the broken tiles in so the Nibblers could start to break the dam. These were the last enemy to go into the game and took a bit of time to get right as I’m working with both objects and tiles for this part whereas the other objects have been just sprites I could throw around. Now that they work perfectly and I’ve made adjustments to where they can go so I’ve always got a chance to be able to destroy them no matter where the helicopter is – remember the helicopter only fires upwards – the game has all the game-play stuff in place. That doesn’t mean it’s finished, however.

This has now given me the opportunity to think of other stuff that does need to get done before I can consider the game finished and there’s still a huge amount of things to get done. I approached Envahi with the intention of getting all the game-play stuff done as quick as possible and then I could work on improving each part in a priority list afterwards. It was done this way so, if I got to a point where I ran out of time, then I would be able to draw a line under the project as it was already still a complete game, if rough around the edges.

I’ve got more work to do with the level structure to make sure that I can keep most people happy with how easy/hard it is to play. I’ve got two testers – three including my partner but she’s not much of a game player so will probably be more helpful telling me what looks OK and what’s terrible. The other two guys, one of whom is obviously Aaron, have played a few games in their time. I’m hoping that they give it enough time, even if initially it seems to difficult, to get good at it so I’ll get a much better idea on any more tuning I need to do.

I also have to stick in some kind of speed-up effect for every event once a grabber takes the player off the screen. At present I deliberately let the events go on where the player can wait for the city to be destroyed or invaded and is helpless because his helicopter got caught. Sometimes it takes too long so I need this in there as a kind of fast-forward on a VCR so players don’t get bored waiting this out.

One other thing to mention is the high score entry music where I’ve settled on an old tracker file of the Infodroid game music from the C64 as composed by Fred Gray. The tracker music was free to use so I’ve converted it with VLC into an MP3 and will use that as I’ve always liked the track.

The last part of my work today was creating a load of sprites and tiles so I could create the flooding of the city when the Dam breaks. This was the major theme of the original game so I want to get this right. The graphics work took a while but I’m happy that’s all done now so it’s the actual code part that I’ll be approaching next visit. When that parts in it’s another 5% towards game completion in my mind.


Categorised as: Development | Envahi | Game Studio 2 | Syntax Bomb

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.