Strategy defence devotees have helped Kingdom Rush, developed by Armor Games, to emerge as the most popular paid-for app for the iPad this week.
The app involves gamers defending their kingdom against orcs, trolls, wizards and other fiends using an arsenal of towers and spells.
Competitors fight on forests, mountains and wastelands, and can adapt their defence strategy with different tower upgrades and specialisations.
The heavily discounted app, currently on sale for 69p, has received favourable reviews from customers who have described it as "addictive" and the "best tower defence game out there".
The game toppled Inspire Pro's Paint, Draw & Sketch from the number one position.
The creative tool, which simulates wet oil paint on a canvas and offers users five kinds of brush to create their own masterpieces, is in second place in this week's paid-for iPad app chart.
Fans of Sunday's Super Bowl helped the NFL Flick Quarterback HD app rise two places to number three, while the Pages word processor app occupies fourth place.
Meanwhile, treasure hunting game Temple Run maintained the number one position in the free app charts for the iPad and iPhone.
The top paid-for iPhone app was WhatsApp Messenger, an instant messenger for smartphones which also secured prime position last week.
The Lost City, said to be inspired by classic point and click adventure games, was in second place.
In third place was Celebalike, which uses facial recognition and scans a database of more than 250 celebrities before returning the closest matches.
The App Store Official UK Charts - Week 5, 2012.
iPhone - Paid Chart:
1. WhatsApp Messenger - WhatsApp Inc
2. The Lost City - Fire Maple Games
3. Celebalike - Ventutec Ltd
4. Fruit Ninja - Halfbrick Studios
5. Theory Test: Driving Test Success - Focus Multimedia
6. Hatchi - Portable Pixels
7. NFL Flick Quarterback - Full Fat
8. Keep Calm And Carry On - Back Bay Bytes LLC
9. Angry Birds - ClickGamer.com
10. The Night Sky - iCandi Apps
iPhone - Free Chart:
1. Temple Run - Imangi Studios, LLC
2. Ski On Neon - Esoteric Development
3. Sliding Tiles - Grabarchuk Puzzles, Kft
4. Tom's Love Letters - Out Fit 7 Inc
5. The Secret Of Grisly Manor - Fire Maple Games
6. Monster Galaxy: The Zodiac Islands - Gala Interactive
7. Top Gear: Stunt School - BBC Worldwide
8. GlassPong - SIGMA Communications Inc
9. Bling My Screen - Tick Tock Apps
10. BBC iPlayer - Media Applications Technologies Ltd
iPad - Paid Chart:
1. Kingdom Rush - Armor Games
2. Inspire Pro: Paint, Draw & Sketch - KiwiPixel
3. NFL Flick Quarterback HD - Full Fat
4. Pages - Apple
5. Weather+ - International Travel Weather Calculator
6. Football Manager Handheld 2012 - Sega
7. The Night Sky - iCandi Apps
8. Catchphrase for iPad - Deluxe Digital Studios London
9. Weather Live - Apalon
10. Reckless Racing 2 - Polarbit
iPad - Free Chart:
1. Temple Run - Imangi Studios, LLC
2. Tom's Love Letters - Out Fit 7 Inc
3. Top Gear: Stunt School HD - BBC Worldwide
4. Sliding Tiles - Grabarchuk Puzzles, Kft
5. LEGO App 4+ - The LEGO Group
6. BBC iPlayer - Media Applications Technologies Ltd
7. Skype for iPad - Skype Software Sarl
8. Sky Sports News for iPad - BSkyB
9. ITV Player - ITV
10. Valentines Day 2012: The Best 14 Free Apps For Your Love - MagicSolver.com Ltd