Aren't you supposed to get better at something if you keep trying? You may, for example, take your midlife crisis in the form of a triathlon and find yourself flailing on your back in the swim portion, looking up to realize that not only are you not doing the smooth front crawl you imagined but you've been heading in the wrong direction for much of the race.

That will probably get better with time – a little more experience and practice, perhaps some therapy.

More time, however, did not help with the two games on offer this week. Both started strong and then faded fast.

First on the bill is Guitar Hero: On Tour for Nintendo's dual-screen portable, the DS. The Guitar Hero brand, built around a series of games that make music interactive using life-size instruments and on-screen cues, has mushroomed over the past three years – few recent trends have been so thoroughly monetized. Walking into a video-game store now feels more like entering a music shop run by Fisher Price, given the number of fake plastic guitars and accessories of all kinds for Guitar Hero and its spiritual successor, the multi-instrument party game Rock Band.

The back catalogue got even larger this week with the addition of not only On Tour but Guitar Hero: Aerosmith, a full-priced console game that tucks a slim biographical chapter into the usual formula of progressing through rock songs with fast fingers. For Aerosmith fans, it amounts to a $60 greatest-hits compilation – a format that will make sense to a lot more people if a rumoured Beatles edition appears – but as expected, this instalment sinks or swims depending on one's opinion of the featured band, and I have never forgiven Steve Tyler, Joe Perry and those other guys for Janie's Got a Gun.

On Tour, on the other hand, does bring something new to the table. The DS isn't a natural venue for a game built around instrumental fun and long lists of songs – the hand-held system still uses tiny cartridges for data storage – but the developers at Vicarious Visions certainly rose to the challenge. They built a glove-like add-on that fits onto the bottom of the DS, in the slot usually reserved for GameBoy cartridges. This adds four buttons – not the usual five – and a padded strap to help you hold the newly bulky DS. You then turn the hand-held on its side, like a book, and press the colour-coded buttons as the notes scroll toward you on the left-side screen. On the right touch screen, you strum with a pick that has a stylus point at the bottom. You can scribble on the animated guitar's whammy bar to add sound effects and more points, and the bonus system can now be activated by shouting into the microphone on the DS or, if you're shy, by tapping the on-screen meter.

It is quite an ingenious piece of engineering, and the software side of the equation does not disappoint. On Tour has about 25 songs, many of them aimed at the born-in-the-nineties crowd, and a full range of play options, including wireless modes that allow two DS users to play co-operatively or competitively.

As time went on and the difficulty level was amped up, however, some issues arose. First, for a series that has taken air guitar to new heights, On Tour doesn't feel anything like playing a guitar. It's more like doing needlepoint on an accordion built for Tiny Tim, and more than ever the game play is Space Invaders with a pop-rock soundtrack.

Second, for anyone with hands bigger than Tiny Tim's, this game becomes a torture device after about 10 minutes. The manual has all kinds of comfort instructions, which is not a good sign, and I had to dig the system into my stomach to keep my wrist straight and cramp-free. It was those positioning issues – not any lack of skill on my part, naturally – that caused my results to degenerate over time.

Still, there is one thing to remember about Guitar Hero and Rock Band: Many of the people who now consider interactive music a hobby thrive on the games' difficulty. The fact they're hard to play is part of the fun. To prove this point, do an online video search for Through the Fire and Flames, a song by British metal band DragonForce that on the “expert” setting may the most insanely challenging test in gaming history. One young player has accurately hit all 3,722 notes in that one, so a little cramping might be considered training. Call it the carpal-tunnel challenge – and take plenty of breaks.

The second game on the schedule, the tennis title Top Spin 3, was put there to coincide with this weekend's Wimbledon finals. Unfortunately, that grass-court classic is the only Grand Slam tournament not included in the game, and only the PlayStation 3 version contains both Roger Federer and Rafael Nadal, two of the most sublimely talented players ever and the likely finalists on Sunday. (The Xbox 360 and Wii editions have Federer but no Nadal, for contractual reasons, and the Wii title looks and acts more like Top Spin 2, for unknown reasons.) What the game does have is a control system that will test even swift-fingered guitar gods and goddesses. To hit something called a “risk shot,” for example, you are told to hold button “A” to prepare a flat shot, hold the right trigger to add power, aim with the left stick, then release “A” to swing. Sounds simple enough.

But despite my long history of real and virtual tennis experience, hitting anything beyond the basic arsenal of ground strokes here took almost perfect timing. Eventually, if you stick with the game's long and slow tutorial sections, it becomes clear that Top Spin 3 works best if you think two or three strokes ahead – you have to be ready to hit your next shot almost before you finish the present one.

That's a good strategic lesson to learn, but the timing issue with the risk shots and volleys often got in the way of putting theory into practice. I like a good challenge, but I would almost – almost – rather go for a swim than wade too much deeper into Top Spin 3's inflexible idea of the perfect stroke.